Roy Hess is Earl Sinclair's best friend and co-worker on Dinosaurs. An affable tyrannosaurus rex, usually addressing Earl as "pally boy," Roy is known to Earl's kids as Uncle Roy. Roy is a bachelor, and has a serious crush on Monica DeVertebrae. He also briefly dated Earl's sister, Pearl.
David Greenaway puppeteered Roy's face. Pons Maar, Roy's suit performer, operated the huge head (held high above his own) from inside the suit, using a small monitor to see the outside world. Roy's tiny animatronic arms were operated with an arm-rig by Julianne Buescher.
Roy also occasionally visits to play chess with the Sinclair family.
- According to the episode "Georgie Must Die," Roy's middle name is "Danger." It was his mother's maiden name, and they wanted to keep it in the family.
- He dressed up like a girl at least 3 times before. He mentioned dressing up like a USO girl in Nuts to War Part 1 before and again, and dressed up like a woman in Working Girl.
- Episode 101: The Mighty Megalosaurus
- Episode 102: The Mating Dance
- Episode 103: Hurling Day
- Episode 104: High Noon
- Episode 105: The Howling
- Episode 201: The Golden Child
- Episode 202: Family Challenge
- Episode 204: Charlene's Tale
- Episode 206: Employee of the Month
- Episode 208: Career Opportunities
- Episode 209: Unmarried ... With Children
- Episode 212: Refrigerator Day
- Episode 213: What "Sexual" Harris Meant
- Episode 214: Fran Live
- Episode 217: A New Leaf
- Episode 218: The Last Temptation of Ethyl
- Episode 219: Nuts to War (part 1)
- Episode 220: Nuts to War (part 2)
- Episode 221: And the Winner Is...
- Episode 224: WESAYSO Knows Best
- Episode 301: Nature Calls
- Episode 303: Baby Talk
- Episode 304: Network Genius
- Episode 305: The Discovery
- Episode 311: Wilderness Weekend
- Episode 312: The Son Also Rises
- Episode 313: Getting to Know You
- Episode 314: Green Card
- Episode 317: Honey, I Miss the Kids
- Episode 319: If I Were a Tree
- Episode 320: We Are Not Alone
- Episode 402: Earl, Don't Be a Hero
- Episode 403: The Greatest Story Ever Sold
- Episode 405: Earl's Big Jackpot
- Episode 407: Changing Nature
- Episode 408*: Into the Woods
- Episode 410*: Working Girl
- Episode 411*: Variations on a Theme Park
- Episode 412*: Life in the Faust Lane
- Episode 413*: Earl and Pearl
- Episode 414*: Georgie Must Die