Bertina is Bert's surfer cousin that appeared in the "Beach" episode of Bert and Ernie's Great Adventures.

Ernie and Bert visit the beach with Bertina and Moose, Bertina's hyper-competitive friend. Moose makes every beach game they play a competition, until he and Bertina get taken by the Big Wave. Bert and Ernie go into Lifeguard-mode to rescue them.