He's a small, brown seal. He's very friendly. A running gag is when he comes up on Fluke and Rudder's rock in which both of them bark, "Off! Off! Off!" (which maybe is a parody on Seagulls saying "Mine! Mine! Mine!") at him. Though he shows no feeling, Gerald is obviously very sad about this, because Fluke and Rudder mistreated Gerald and stole his green pale, despite Gerald was being friendly and gave it to them. Ultimately, however, he managed to sneak onto their rock as they sleep becoming the victor.
History
Gerald first appeared when Fluke and Rudder and Marlin and Nemo discussed about the Institute in which Fluke and Rudder were barking "Off! Off! Off!" to shoo Gerald. their discussion with Marlin and Nemo, causing the sea lion to swim away. Gerald next appears when Fluke and Rudder told him to arrive closer in which the two trick him in an attempt to sit on their rock for a while. By doing this, the two sea lions let him sit on their rock for a bit. Once they declared that time's up, they shooed off Gerald again and leaving the pail for Becky to pick up Marlin and Nemo to help find and rescue Dory in the Marine Life Institute. Gerald later appeared during the climax scene when Fluke and Rudder watched the excitement of Dory preparing to save Marlin, Nemo, and the rest of the fish inside the truck (despite they weren't helping Dory) in which their rock is promptly taken over by Gerald. They let him sit there for now, but told him to leave whenever they got back. In the post-credits, Gerald appeared when he was testing if Fluke and Rudder would react if he touches their rock. His hypothesis worked as he is shooed off again. After Fluke and Rudder witnessed the Tank Gang taken by Marine Life Institute volunteers before resuming their nap, Gerald last appeared when he finally managed to sneak onto the rock unnoticed, giving a devious chuckle.
Disney Heroes: Battle Mode
Gerald along with Marlin and Nemo appear in the game as a trio of characters after Huey, Dewey, and Louie, they both attack by spitting while Gerald uses his seal cries to silence enemies and attracts a flock of seagulls to attack the enemies.