Accidently eating the fish that he is trying to help
Powers and abilities
Ejects Marlin and Dory through his blowhole and dives back underwater, discovering he was helping them get to Sydney and not eating them (Finding Nemo). Swims with Crush through the EAC (Finding Dory).
In Finding Nemo, the whale is first seen from a distance before he reveals how large he is. Dory starts speaking whale to try and ask him if he can help them find Nemo, but the whale ends up swimming away. But then slowly (and rather ominously) he swims up behind Marlin and Dory (also scaring some krill, who tell the two fish to swim away), and swallows Marlin and Dory whole. Later, while Marlin struggles to get out, Dory tries to speak to the whale again. In reaction, the whale ejects the two fish from his blowhole at a convenient location which happens to be Sydney. The whale theoretically understood Dory and helped her and Marlin get to their destination.
In Finding Dory, the whale makes a cameo appearance in the scene where Marlin, Dory and Nemo travel through the EAC with Crush to find Dory's parents Jenny and Charlie.
World of Color
The whale appears in the show's version of the sequence of Dory speaking whale and is the lead-in to the Pines of Rome sequence.