Mortimer Bunny is one of Babs Bunny's many younger siblings on Tiny Toon Adventures. He makes three cameo appearances, in Prom-ise Her Anything and the Pledge Week episode segments, It's All Relatives and Lifeguard Lunacy.
Prom-ise Her Everything
In Prom-ise Her Anything, while Babs is impatiently waiting for Buster, and literally climbing up the walls for him, the phone rings and Mortimer (who is shown to be a young orange rabbit) tries to pick up the phone, but is stopped by Babs, who points her pickaxe at him.
It's All Relatives
In the Pledge Week episode segment, It's All Relatives, Mortimer appears near the end, after Babs dishes out a montage of her funny impressions to remember what the funny thing she did was the last time that Nana visted. Both Babs' Mother and Grandmother are impressed when Mortimer sits up on his own (only to fall over later). This version of Mortimer is shown to be a baby rabbit with blue fur, similar to what Buster looked like when he was a baby. He also makes a cameo appearance in the following episode segment, Lifeguard Lunacy, where he is seen playing ball with Li'l Sneezer and Drooley Davey.