The following is a list of the characters who have not as of yet been seen in the Great Valley, but have been prominent at least once in scenes in other places, such as The Mysterious Beyond or The Land of Mists.
Archie is an old Archelon, an extinct species of turtle. He lives in a cave just outside of the Land of Mists. He has only ever appeared in The Land Before Time IV: Journey Through the Mists.
Look, look, look what they're doing! They're so greedy!
— Cera, The Land Before Time
Hidden Runner is a dark and light green and blue Troodon. Voiced by Rob Paulsen (TV series). The only appearance, so far, as been in the TV series Episode The Spooky Nighttime Adventure. He has the ability to blend in with its habitat due to its multi-colored markings, giving the impression that it can turn invisible. He maybe eat plants instead of meat.
Mo's Water Kin
Sue is a bright pink Supersaurus, and she is most well known for defending Littlefoot from a belly dragger by stepping on it, in The Land Before Time X: The Great Longneck Migration. Not much is known about Sue, due to her short appearances in the film. So far what we know about her personality is she's kind. Sue gets a boyfriend in the crater, and leaves with him. Sue is voiced by Bernadette Peters.
Tickles is a Megazostrodon who appears in The Land Before Time IV: Journey Through the Mists.
Tickles's family appear in the branches of a tree, connecting them to the inconveniencing creatures who had crowded the Longnecks out of their feeding grounds. They appear again when the gang first meets Tickles.