Mo is a colourful Opthalmosaurus, which is referred to as a "swimmer" (which also describes any animal in The Land Before Time series which swims) in The Land Before Time films and TV series. He is referred to by Littlefoot as his "mud brother". He will meet Winnie the Pooh, Ash Ketchum, and their friends in Pooh's Adventures of The Land Before Time IX: Journey to Big Water.

TriviaEdit

• Mo was briefly seen during the underwater sequence of the Disneyland version of Winnie The Pooh In Fantasmic!, even though he has yet to appear in a Pooh's Adventures film.
• Mo will see Pooh, Ash, and their friends again in one episode of the Pooh's Adventures of The Land Before Time TV series.
• Mo will meet SpongeBob SquarePants, Mickey Mouse, Bugs Bunny, and their friends in SpongeBob's Adventures of The Land Before Time IX: Journey to Big Water.
• Mo will see SpongeBob, Mickey, Bugs, and their friends again in one episode of the SpongeBob's Adventures of The Land Before Time TV series.
• Mo will make his first guest appearance in a Land Before Time crossover film in Littlefoot's Adventures of Free Willy, in which Willy the Whale is his closest friend.
• Mo will see Littlefoot and his friends again in Littlefoot's Adventures of Free Willy: Yuletide and Redtide, Littlefoot's Adventures of All Dogs Go to Heaven, Littlefoot's Adventures of Free Willy 2: The Adventure Home, Littlefoot's Adventures of All Dogs Go to Heaven 2, Littlefoot's Adventures of The Little Mermaid: Ariel's Beginning, Littlefoot's Adventures of The Little Mermaid, Littlefoot Meets The Swan Princess, Littlefoot's Adventures of Pinocchio, Littlefoot's Adventures of Free Willy 3: The Rescue, and Littlefoot in Fantasmic!.