Marlin is the protagonist of Disney/Pixar's 2003 animated film Finding Nemo and the tritagonist of its 2016 sequel. He is the widower of Coral and father of Nemo and 399 unborn clownfish.
It's like Best and Worst of Villains, but for fictional heroes.
BTW, if anyone copies this (which might be likely since I've seen a few duplicate casts in categories like this one), this is the original.