Yellowtail is fair-skinned like his children. He has a light blonde beard and eyebrows and wears a bright yellow raincoat, with two white/very light green stripes near the bottom, a bright yellow rain hat, and pale blue rain boots. In "Onion Friend" a younger version of himself appears in a picture; he has no large beard and appears to have a small tuft of hair similar to Onion. Also like his son, he has no visible ears.
Yellowtail, like his son Onion, speaks in gibberish but seemingly intelligible language, as revealed in "Onion Trade". He cares a lot about Onion, but his job as a sailor leaves him with little time to see him. He may be a somewhat old-fashioned father, as he seems to want his step-son Sour Cream to follow in his footsteps as a fisherman, instead of following his dreams of being a DJ. However, despite their somewhat strained relationship, he still cares a lot about his step-son, which eventually made him change his mind and approve of Sour Cream's decision to become a DJ. He also seems to dislike Sour Cream's biological father Marty, notably after learning that he ruined his step-son's show.
Onion throws food into the ocean at the Beach City Pier, which causes Yellowtail to appear on his boat. Yellowtail lifts up his son and the two talk in their language. Then, Yellowtail jumps back on the boat and sails away, waving to his son.
Yellowtail tries to get his boat washed at It's a Wash, but it is too big to fit into the car wash. Steven teleports back in time to tell Greg that the boat is too fat to fit into the car wash, which accidentally causes Yellowtail's car to roll into an electrical pole, knocking the pole down onto Yellowtail's car and setting the car wash on fire. Steven travels back in time once more to prevent that from happening, thus making Yellowtail's boat stuck in the car wash once more.
When the ocean returns, Yellowtail and Greg put their arms around each other, while the former hands Greg a handkerchief to blow his nose as he cries.
Yellowtail, Sour Cream, and Onion get out of their car to make sure Steven is okay when he flies out of Greg's Van.
Yellowtail is seen sitting on the beach with Onion.
Vidalia reveals that she and Yellowtail had been married for a while. Vidalia talks about how Yellowtail is always out at sea somewhere. She also reveals that when Sour Cream DJs in the house, it drives Yellowtail nuts, and that they are always at each other's throats.
Yellowtail returns to his house with a briefcase filled with fish and water leaking out. He notices Sour Cream's wagon full of DJ equipment which makes him drop his suitcase and talks to him in their language. With translations from Sour Cream, Yellowtail orders Sour Cream to be back before 10, and tells him that DJing isn't a viable career. Sour Cream later tells Marty that Yellowtail never has talked with him. Later on, Yellowtail can be seen from his boat, watching Sour Cream and Marty interact with binoculars, which makes him worried. At Sour Cream's rave, Steven reveals that the Guacola portion was set up by Marty, which makes Yellowtail furious. Yellowtail sprints to his boat and later returns with a box full of Sour Cream's old DJ equipment, asking him to play. Yellowtail then hugs Sour Cream and is later seen dancing next to Vidalia with Onion resting on his head.
Vidalia is seen painting Yellowtail in his underwear in their driveway.
Yellow goes to It's a Wash after hearing what the Crystal Temps were able to do to Mayor Dewey's Van. Peridot lifts up Yellowtail's car, while he is still in it, and then Lapis summons a water hand to grab it. Yellowtail panics as Peridot and Lapis fight, knocking him out of his own car, but he safely lands in Jenny's Car. Peridot and Lapis accidentally launch Yellowtail's car into the It's a Wash sign.
Yellowtail's folded name card is partially concealed from view by Pearl's folded name card.
Yellowtail and Vidalia came to the show where his stepson Sour Cream is. The Diamond Mech flew down above the stage, and bemusement was all that was left for Yellowtail.
Yellowtail doesn't see his son often as he appears to be a sailor, but they've shown to have a very good father-son relationship when together, as seen in "Onion Trade".
Yellowtail was shown supporting Greg to help him stand in "Ocean Gem" due to Greg's injured leg, as well as lending him a tissue when he got emotional after seeing Steven be praised by the crowd. However, in "Steven and the Stevens", when Greg warns him that the boat might be too big to fit the car wash, he looks reasonably angry. They may be friends, or simply acquaintances.
Yellowtail is Sour Cream's step-dad, but their relationship appears to be strained due to his disapproval of Sour Cream's choice to become a DJ instead of a fisherman like himself. According to Vidalia, the two fight very often. In "Drop Beat Dad", Yellowtail originally does not support Sour Cream being a DJ, but by the end of the episode, he gives Sour Cream his old DJ equipment and can be seen dancing in the crowd at Sour Cream's rave.
Vidalia and Yellowtail are married. However, as Yellowtail is often out at sea, most of their relationship is unknown. In "Onion Gang", Yellowtail is seen modeling for Vidalia.
While they have yet to interact with each other, Yellowtail seems to be aware of Marty being Sour Cream's biological father. He does not appear to trust him spending time with his step-son, keeping an eye on them from a distance while on his boat. After learning that Marty ruined Sour Cream's show, he became furious with Marty and ran away to his boat to gather Sour Cream's old DJ equipment in order to help his step-son.
|1. "Gem Glow":||Absent||14. "Lars and the Cool Kids":||Absent|
|2. "Laser Light Cannon":||Absent||15. "Onion Trade":||Debut|
|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":||Absent|
|7. "Bubble Buddies":||Absent||20. "Coach Steven":||Absent|
|8. "Serious Steven":||Absent||21. "Joking Victim":||Absent|
|9. "Tiger Millionaire":||Absent||22. "Steven and the Stevens":||Appears|
|10. "Steven's Lion":||Absent||23. "Monster Buddies":||Absent|
|11. "Arcade Mania":||Absent||24. "An Indirect Kiss":||Absent|
|12. "Giant Woman":||Absent||25. "Mirror Gem":||Absent|
|13. "So Many Birthdays":||Absent||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":||Absent||46. "Open Book":||Absent|
|34. "Watermelon Steven":||Absent||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":||Absent|
|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":||Absent||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":||Pictured||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":||Absent||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":||Absent||22. "Beta":||Absent|
|10. "The New Lars":||Absent||23. "Earthlings":||Absent|
|11. "Beach City Drift":||Absent||24. "Back to the Moon":||Absent|
|12. "Restaurant Wars":||Absent||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":||Flashback|
|4. "Mindful Education":||Absent||17. "Storm in the Room":||Absent|
|5. "Future Boy Zoltron":||Absent||18. "Rocknaldo":||Absent|
|6. "Last One Out of Beach City":||Absent||19. "Tiger Philanthropist":||Absent|
|7. "Onion Gang":||Non-speaking||20. "Room for Ruby":||Absent|
|8/9. "Gem Harvest":||Absent||21. "Lion 4: Alternate Ending":||Absent|
|10. "Three Gems and a Baby":||Pictured||22. "Doug Out":||Absent|
|11. "Steven's Dream":||Absent||23. "The Good Lars":||Pictured|
|12. "Adventures in Light Distortion":||Absent||24. "Are You My Dad?":||Absent|
|13. "Gem Heist":||Absent||25. "I Am My Mom":||Absent|
|1. "Stuck Together":||Absent||15. "Pool Hopping":||Absent|
|2. "The Trial":||Absent||16. "Letters to Lars":||Absent|
|3. "Off Colors":||Absent||17. "Can't Go Back":||Absent|
|4. "Lars' Head":||Absent||18. "A Single Pale Rose":||Absent|
|5. "Dewey Wins":||Absent||19. "Now We're Only Falling Apart":||Absent|
|6. "Gemcation":||Absent||20. "What's Your Problem?":||Absent|
|7. "Raising the Barn":||Absent||21. "The Question":||Absent|
|8. "Back to the Kindergarten":||Absent||22. "Made of Honor":||Absent|
|9. "Sadie Killer":||Absent||23/24. "Reunited":||Non-speaking|
|10. "Kevin Party":||Absent||25. "Legs From Here to Homeworld":||Absent|
|11. "Lars of the Stars":||Absent||26. "Familiar":||Absent|
|12. "Jungle Moon":||Absent||27. "Together Alone":||Absent|
|13. "Your Mother and Mine":||Absent||28. "Escapism":||Absent|
|14. "The Big Show":||Absent||29-32. "Change Your Mind":||Non-speaking|
- Yellowtail is named after the fish of the same name, corresponding to the fact that he is a sailor. Together with Vidalia, Onion, and Sour Cream, his entire family is named after food.
- The original character art (posted in the Steven Universe crew's Tumblr) shows that his name is Yellowtail.
- His name was confirmed in "Onion Friend".
- Whenever Yellowtail speaks, he doesn't use words, he only says "Muh Muh Muh Muh..." similar to the "Wah Wah Wah" lines commonly used by the unseen adult characters from the Peanuts comic strip series by Charles M. Schulz.
- In a picture on the wall seen in "Onion Friend", his younger self looks similar to Clarence, the title character in another Cartoon Network show.
- As of "Drop Beat Dad", Yellowtail seems more accepting of Sour Cream's career path.