Onion is a minor character in Steven Universe and a resident of Beach City. He made his debut in "Laser Light Cannon" as a cameo character. As revealed in "Onion Friend", he is the son of Yellowtail and Vidalia and the half-brother of Sour Cream.
Onion is a fair-skinned boy with a small tuft of blond hair and a chubby face. He wears a white sweater, a deep periwinkle shirt tied around his neck, and pale red footie pants. His most recognizable trait is his onion-like head (although the top is thinner than the bottom, not resembling a normal onion). He also does not have any visible ears.
Onion is a a comparatively quiet character who does not speak except to his parents, and then sparingly. He speaks in a gibberish language that is apparently intelligible by most characters, but that is not spoken by anyone else except his father (and Sour Cream on rare occasions). He is also capable of understanding basic English and will occasionally respond to direct questions in English with simple gestures, as is shown in "Onion Friend." Onion is eager to help people. He will blindly follow orders even if they don't seem very well thought out, such as in the episode "Bubble Buddies", when he shot a harpoon at Steven's bubble. He cannot stand being lied to, especially by close friends, as shown in "Steven's Lion".
He has been seen to indulge in criminal activities, particularly thieving. In "So Many Birthdays", as he is seen stealing tickets from an arcade machine, which explains how he had enough to win a moped in "Arcade Mania". This is further emphasized in "Onion Trade" with Onion's delinquent behaviors such as destroying the moped for no apparent reason. He also stole Steven's Chaaaaps and Ranger Guy in the episodes "Onion Friend " and "Onion Trade ", respectively. Onion's delinquent and kleptomaniacal behavior can be attributed to his severe loneliness as a grab for attention, due to his father constantly being at sea. He does not seem to understand or simply not care when and if he is hurting people, has no qualms with stealing what he wants, and does things obliviously in the name of fun. This could be attributed to his young age and lack of moral understanding. He continues his bad acts in "Watermelon Steven", when he steals Steven's Baby Melon, despite Steven stating he wasn't for sale. In "Political Power", Onion seems to be on the verge of attacking Mayor Dewey as he held his baseball bat menacingly.
Later, in "Too Short to Ride", the severity of his criminal acts appear to have escalated. He is shown preparing to burn down the roller coaster at Funland when it had people on it, with implications that it wasn't his first attempt. In "Future Boy Zoltron", Onion is shown about to terrorize Funland Arcade with a crowbar. At this point Steven starts to worry that Onion will end up in prison.
He has also been shown to have a rather strange fixation with food, in that he is never seen eating it but instead throwing or destroying said food as said by Steven and proven in "Onion Trade" and "Onion Friend". The only food he does seem to enjoy is Guacola, as he is seen taking several sips in "Drop Beat Dad". He seems to have an overall strange personality, as he is a very difficult person to understand and predict.
Steven is Onion's friend whom he has known in the past and is eager to help. They may get along, but it is a one-sided relationship as Onion isn't known to talk to anyone but his father and his mother. However, his mother says that Onion talks a lot about Steven. Steven seems to wonder what Onion is doing most of the time. In "Onion Friend", Onion seems to do certain actions specifically to push Steven's buttons as a form of childish teasing, wasting food intentionally knowing that it bothered Steven and pretending to feed a mouse to his pet snake in order to scare him. He also seems to steal from Steven pretty often, from his Ranger Guy to his bag of chips. Onion however, is shown to care about Steven as he gave him his Explorer Gal as well as show him his collection of G.U.Y.S and G.A.L.S in his secret room. Steven also seems concerned about Onion's criminal behavior, telling him he has a future in prison if he continues. Despite his teasing of Steven, deep down he considers him one of his best friends, even introducing him to his summer friends before they had to go back to school.
Onion doesn't see his father often due to him being at sea most of the time, and this causes Onion to spend a lot of time wandering around, unsupervised. When Onion does see his father, he has been shown to speak to him in an unknown language. Yellowtail is one of the people Onion has been shown to speak to.
Vidalia, his mother, shows a very close relationship, with her being the only other person he talks aloud to, albeit just the word "mama". She also encourages his expressive nature. Whether she is aware of Onion's strange and unnerving activities is currently unknown.
Onion and Connie have only met once in "Bubble Buddies", but Onion has been shown to be able to understand Connie easier than Steven, shown when she spelled "Harpoon Gun" backwards on the bubble shield they were trying to pop, while Steven attempted to draw one.
Onion and Sour Cream have never been seen interacting, although they are shown together in the evacuation of Beach City in "The Return" and the opening theme. In "Joy Ride", it is confirmed that Sour Cream and Onion are related. Explored further in "Onion Friend", it is confirmed that they are half-brothers.
In "Onion Trade", Onion enters Suitcase Sam's and is given a hamburger by him, for unknown reasons. They may possibly be friends, given Suitcase Sam's giving Onion a hamburger. He also has a poster of Suitcase Sam on his wall in his room; revealed in "Onion Friend".
They are Onion's friends whom he spends time with during the summer. Together they enjoy lots of mischief, such as riding in a homemade go-kart, taking surprise photos of the people of Beach City, and racing bugs. Sadly however they do not live in Beach City, and leave for school in the fall.
|1. "Gem Glow":||Absent||14. "Lars and the Cool Kids":||Absent|
|2. "Laser Light Cannon":||Debut||15. "Onion Trade":||Appears|
|3. "Cheeseburger Backpack":||Absent||16. "Steven the Sword Fighter":||Absent|
|4. "Together Breakfast":||Absent||17. "Lion 2: The Movie":||Absent|
|5. "Frybo":||Absent||18. "Beach Party":||Absent|
|6. "Cat Fingers":||Absent||19. "Rose's Room":||Cameo|
|7. "Bubble Buddies":||Appears||20. "Coach Steven":||Absent|
|8. "Serious Steven":||Absent||21. "Joking Victim":||Absent|
|9. "Tiger Millionaire":||Absent||22. "Steven and the Stevens":||Absent|
|10. "Steven's Lion":||Absent||23. "Monster Buddies":||Absent|
|11. "Arcade Mania":||Cameo||24. "An Indirect Kiss":||Absent|
|12. "Giant Woman":||Appears||25. "Mirror Gem":||Absent|
|13. "So Many Birthdays":||Cameo||26. "Ocean Gem":||Cameo|
|27. "House Guest||Absent||40. "On the Run":||Absent|
|28. "Space Race":||Absent||41. "Horror Club":||Absent|
|29. "Secret Team":||Absent||42. "Winter Forecast":||Absent|
|30. "Island Adventure":||Absent||43. "Maximum Capacity":||Absent|
|31. "Keep Beach City Weird":||Absent||44. "Marble Madness":||Absent|
|32. "Fusion Cuisine":||Absent||45. "Rose's Scabbard":||Absent|
|33. "Garnet's Universe":||Pictured||46. "Open Book":||Absent|
|34. "Watermelon Steven":||Appears||47. "Shirt Club":||Absent|
|35. "Lion 3: Straight to Video":||Absent||48. "Story for Steven":||Absent|
|36. "Warp Tour":||Absent||49. "The Message":||Absent|
|37. "Alone Together":||Absent||50. "Political Power":||Cameo|
|38. "The Test":||Absent||51. "The Return":||Cameo|
|39. "Future Vision":||Absent||52. "Jail Break":||Absent|
|1. "Full Disclosure":||Cameo||14. "Historical Friction":||Absent|
|2. "Joy Ride":||Absent||15. "Friend Ship":||Absent|
|3. "Say Uncle":||Absent||16. "Nightmare Hospital":||Absent|
|4. "Love Letters":||Absent||17. "Sadie's Song":||Absent|
|5. "Reformed":||Absent||18. "Catch and Release":||Absent|
|6. "Sworn to the Sword":||Absent||19. "When It Rains":||Absent|
|7. "Rising Tides, Crashing Skies":||Cameo||20. "Back to the Barn":||Absent|
|8. "Keeping It Together":||Absent||21. "Too Far":||Absent|
|9. "We Need to Talk":||Absent||22. "The Answer":||Absent|
|10. "Chille Tid":||Absent||23. "Steven's Birthday":||Absent|
|11. "Cry for Help":||Absent||24. "It Could've Been Great":||Absent|
|12. "Keystone Motel":||Absent||25. "Message Received":||Absent|
|13. "Onion Friend":||Appears||26. "Log Date 7 15 2":||Absent|
|1. "Super Watermelon Island":||Absent||13. "Kiki's Pizza Delivery Service":||Absent|
|2. "Gem Drill":||Absent||14. "Monster Reunion":||Absent|
|3. "Same Old World":||Absent||15. "Alone at Sea":||Absent|
|4. "Barn Mates":||Absent||16. "Greg the Babysitter":||Absent|
|5. "Hit the Diamond":||Absent||17. "Gem Hunt":||Absent|
|6. "Steven Floats":||Imagined||18. "Crack the Whip":||Absent|
|7. "Drop Beat Dad":||Appears||19. "Steven vs. Amethyst":||Absent|
|8. "Mr. Greg":||Absent||20/21. "Bismuth":||Absent|
|9. "Too Short to Ride":||Appears||22. "Beta":||Absent|
|10. "The New Lars":||Appears||23. "Earthlings":||Absent|
|11. "Beach City Drift":||Absent||24. "Back to the Moon":||Absent|
|12. "Restaurant Wars":||Cameo||25. "Bubbled":||Absent|
|1. "Kindergarten Kid":||Absent||14. "The Zoo":||Absent|
|2. "Know Your Fusion":||Absent||15. "That Will Be All":||Absent|
|3. "Buddy's Book":||Absent||16. "The New Crystal Gems":||Absent|
|4. "Mindful Education":||Absent||17. "Storm in the Room":||Absent|
|5. "Future Boy Zoltron":||Non-speaking||18. "Rocknaldo":||Cameo|
|6. "Last One Out of Beach City":||Absent||19. "Tiger Philanthropist":||Absent|
|7. "Onion Gang":||Appears||20. "Room for Ruby":||Absent|
|8/9. "Gem Harvest":||Absent||21. Lion 4: Alternate Ending":||Absent|
|10. "Three Gems and a Baby":||Absent||22. "Doug Out":||Appears|
|11. "Steven's Dream":||Absent||23. "The Good Lars":||Absent|
|12. "Adventures in Light Distortion":||Absent||24. "Are You My Dad?":||Appears|
|13. "Gem Heist":||Absent||25. "I Am My Mom":||Appears|
|1. "Stuck Together":||Absent|
|2. "The Trial":||Absent|
|3. "Off Colors":||Absent|
|4. "Lars' Head":||Absent|
|5. "Dewey Wins":||Appears|
|7. "Raising the Barn":||Appears|
|8. "Back to the Kindergarten":||Absent|
|9. "Sadie Killer":||Absent|
|10. "Kevin Party":||Absent|
|11. "Lars of the Stars":||Absent|
|12. "Jungle Moon":||Absent|
- "We Are the Crystal Gems" (cameo)
- Onion is seen behind Connie in the original intro where Mr. Smiley stops him from running out into traffic.
- He can also be seen on the roof of The Big Donut in the second intro.
- So far, Onion has only communicated with his dad and mother, and all of his dialogue has been very similar to Yellowtail's. This can be heard more clearly in "Onion Gang".
- Rebecca Sugar first hinted in a Reddit AMA that Sour Cream and Onion are related. "Joy Ride" later depicted Sour Cream referring to Yellowtail as his stepdad, and "Onion Friend" confirmed that Sour Cream and Onion are half-brothers. This makes them a play on "Sour Cream and Onion", a popular flavor of potato chips.
- Steven has been shown to doubt if Onion is human in "Marble Madness".
- Onion seems to have a phone, despite that he has never been seen to speak to anyone other than Yellowtail and Vidalia. It's shown that Steven has him in his phone's contact list in "The Return".
- As Onion understands English, it is possible that he and Steven can communicate more easily through texting.
- Onion owns a pet snake, which he tries to get Steven to feed with a mouse found in his room.
- In the comic story Lion Tamer, Onion is seen at a pet contest walking a pet alligator.
- Onion owns an impressive collection of both toy G.U.Y.S. and G.A.L.S. which includes a Red Variant of Ninja Guy, Hardhat Gal, Triangle Gal, Orange Gal, Karen, and Explorer Gal, the last of which he proceeds to give to Steven.
- Onion owns a poster of The Door in his room; an obvious reference to the 1960s rock band The Doors.
- Onion is described as "???????" in "Rising Tides, Crashing Skies" while being interviewed.
- The bat that Onion held in "Political Power" originally had nails in it during storyboarding, but they were removed in the final version.
- The flyers that were used when Onion went missing had "MISSING" written over "Wanted", indicating that Onion is a wanted criminal.
- Rebecca Sugar admits that she doesn't remember on what inspired Onion but that his personality was inspired by her step-brothers.