Rex Owen is Max's best friend. Rex was found as an infant by paleontologist Dr. Owen in an egg-like container within a dinosaur exhibit in New York. Rex is now 12 and has been left with Max and his family while his father goes searching for fossils with Dr. Owen being a family friend of the Taylor family. It is revealed in one episode that Rex was left at Max's house because his father wanted him to be near a real family. Rex's partner is a Carnotaurus he named Ace. Rex also owns most of the fire and wind dinosaurs. Rex is a good-hearted boy and is relatively quiet, but also quite short-tempered from the beginning. At the end of the first series, it is revealed that Rex's real parents are Dr. Ancient and Dr. Cretacia and Rex reunites with them. In the finale, Rex, the Alpha Gang, Seth, Chomp, Ace, Paris and the Ancients return to the year 2126.
Rex played Dale in Max and Rex Rescue Rangers
Rex played Genie in Maxladdin (DinosaurKingRockz), Maxladdin 2: The Return of Merlock, and Maxladdin 3: Maxladdin and the King of Thieves
Rex played Duckworth in ChildTales, and ChildTales the Movie: Treasure of the Lost Lamp
Rex played Brock in Pokemon (Ooglyeye Style)
Rex played Finn in Tai Chi Chasers (1701Movies Human Style)
Rex played Kovu in The Child King 2: Max's Pride
Rex played Edd/Double D in Maui, Rex 'n' Max
Rex played Andrew in Sailor Zoe, and Sailor Zoe (VIZ)
Rex played Dr. David Q. Dawson in The Great Taylor Detective
Rex Played Robomunk In Jimmy and the Boys
Rex Owen Played Fre Jones In Scooby Doo spoof for 1986movies
Rex Owen Played ??? In Thubelina Spoof for 170Movies
Rex Owen Played Darry/Suit Mask In Sailor Venus (Chris1988 Style)
Rex Owen Played Chip In Rex n Dan Rescue Rangers
Rex played Brick in The Powerpuff Girls (397Movies Human Style)
Rex Played Kakeru In Sailor Jupiter S: Hearts in Ice (165Movies Style)
Rex Played Barry In Pokemon Diamond and Pearl (220Movies Style)
He Played Stanley Ipkiss In The Mask (397Movies Style)
He Played Dimitri In Minastasia
- In Dinosaur King (TheBluesRockz Animal Style) he is played by Dale.
- In Dinosaur King (DinosaurKingRockz Style) he is played by Po.
- In Dinosaur King (Chris1701 Style) he is played by Jaune Tom.
- In Dinosaur King (1701Movies Style) he is played by Scooby Doo.
- In Dinosaur King (400Movies Animal Style) he is played by Tony Toponi.
- In Dinosaur King (399Movies Animal Style) he is played by Timothy Q. Mouse.
- In Dinosaur King (397Movies Human Style) he is played by Andrew.
- In Dinosaur King (Chris2015 Style) he is played By Bravo.
- In Dinosaur King (154Movies Style) he is played By Maui
- In Dinosaur King (143Movies Human Style) he is played by Tor.
- In Dk 1987Movies He is Played by Himself
- In Dinosaur King (180Movies Style) He is Played by Chip
- In Dinosaur King spoof for 160Movies he is played by ???.