Kelsey is fairly short when compared to her friends Craig and J.P. She has peach skin, light red hair tied into a bun at the back of her head, and thick, dark red eyebrows. She also has Mortimor, a yellow and green bird that sits on her head most of the time.
Kelsey wears a blue-gray T-shirt with a heart on it, and also wears pink shorts. In the pilot, her shoes are green and have a white bottom, but in the series, she wears blue boots. She has a dark blue cape that she wears around her neck.
Kelsey is very dramatic, in that she often narrates her life in her head in a style akin to theater.
She likes reading, as shown in "The Final Book", and is very upset when she can't find the last book in her favorite series. Kelsey says she spent years reading the young adult series and threatens the librarian when he says he can't tell Kelsey who took the book she's looking for. She often bonds with Stacks over their favorite books, even going so far as to form a book club together in Secret Book Club.
Kelsey can be reckless sometimes. Kelsey also sometimes doesn't consider people's feelings and doesn't think before she acts.
Kelsey always carries her iconic sword with her, formed from a cardboard handle and a cut of PVC pipe. ("Quarter-inch construction-grade PVC pipe with a smooth finish", according to Piper) It is a gift from her father, and holds high sentimental value to her.
In Kelsey the Worthy, it is shown that her sword was forged even before she adopted her current bird Mortimor, cut by Piper at Big Boy Roy's Lumber Shack. To this day, Piper remembers the exact cut and materials used, as people usually just used their piping for toilets.
- In the pilot, Kelsey had green boots.
- In "You're It", it is revealed that her father is the only parent for Kelsey. And considering Kelsey's comment about being “half-orphan” in the episode “Kelsey Quest”, it's to be assumed that her mother passed away, possibly when Kelsey was at a very young age. This assumption is proven in "The Takeout Mission" when it is revealed that she did, in fact, pass away.
- Kelsey was and in some ways, still is, very close to her deceased mother. Her mother read her bedtime stories (which may have been the source of her love of books), and in "Alone Quest" Kelsey thanks her mother for the beautiful day.
- Kelsey is one of the only characters to be recast in the series, next to Earl Williams and Jessica Williams.
- In "The Invitation", Kelsey revealed the only dish she knew how to make was the Hungarian dish chicken paprikash, suggesting she is of Hungarian heritage.
- In "Doorway to Helen", it is hinted at that Kelsey may be Jewish as she refers to her grandmother as her bubbe.
- In "Big Pinchy", it is revealed that she is camera-shy.
- In "The Takeout Mission", she mentioned that she is 8.
- In "The Shortcut", it appears that Kelsey is a tough trader.
- In "Alone Quest", it is revealed that Kelsey is writing a book, "Robyn and the Snow Sword", which is what has been hiding behind the door that says "Keep Out J.P.".
- Kelsey makes a cameo in the OK K.O.! Let's Be Heroes episode "Crossover Nexus" as one of the Cartoon Network heroes that were summoned and turned to stone by Strike.
- In "Turning the Tables", Kelsey is seen doing the hype.
- In The Williams Family Opening Theme Song it is revealed that Kelsey's last name is Pokoly.
- Kelsey does not like pineapple on pizza.
- Pilot (debut)
|1. "Itch To Explore":||Debut||21. "Ace of Squares":||Appears|
|2. "You're It":||Appears||22. "Doorway to Helen":||Appears|
|3. "Jessica Goes to the Creek":||Appears||23. "The Last Kid in the Creek":||Appears|
|4. "The Final Book":||Appears||24. "The Climb":||Appears|
|5. "Too Many Treasures":||Appears||25. "Big Pinchy":||Appears|
|6. "Wildernessa":||Appears||26. "The Kid from 3030":||Appears|
|7. "Sunday Clothes":||Appears||27. "Power Punchers":||Appears|
|8. "Escape from Family Dinner":||Appears||28. "Creek Cart Racers":||Appears|
|9. "Monster in the Garden":||Appears||29. "Secret Book Club":||Appears|
|10. "The Curse":||Appears||30. "Jextra Perrestrial":||Appears|
|11. "Dog Decider":||Appears||31. "The Takeout Mission":||Appears|
|12. "Bring Out Your Beast":||Appears||32. "Dinner at the Creek":||Appears|
|13. "Lost in the Sewer":||Appears||33. "Jessica's Trail":||Flashback|
|14. "The Future is Cardboard":||Appears||34. "Bug City":||Appears|
|15. "The Brood":||Appears||35. "Deep Creek Salvage":||Appears|
|16. "Under the Overpass":||Appears||36. "The Shortcut":||Appears|
|17. "The Invitation":||Appears||37. "Dibs Court":||Appears|
|18. "Vulture's Nest":||Appears||38. "The Great Fossil Rush":||Appears|
|19. "Kelsey Quest":||Appears||39. "The Mystery of the Timekeeper":||Appears|
|20. "Jpony":||Appears||40. "Alone Quest":||Appears|
|1/2. "The Other Side: The Tournament":||Appears|
|3. "The Ground Is Lava!":||Appears|
|4. "Council of the Creek: Operation Hive-Mind":||Appears|
|5. "The Bike Thief":||Appears|
|6. "Craig of the Beach":||Appears|
|1. "Craig of the Car":||Appears|
|2. "How Was Your Day?":||Appears|
|3. "The Williams Family Opening Theme Song":||Appears|
|4. "How to Map the Creek":||Appears|
|5. "Creek Kid Rap":||Appears|