Pacu is a friendly fish, known for his cheerful and supportive demeanor in the animated world. He is often seen swimming in the river and interacts warmly with Marty, showing a genuine interest in his storytelling activities at the Drawing Board. Though he cannot join Marty in this episode due to school commitments, his brief appearance highlights his reliability and willingness to help when possible. Pacu's presence adds a sense of community and continuity to Marty's adventures in the Land of Animation.

His human equivalent age is 11-14.