The Rat King

Personality
Despite his restricted vocabulary the King Rat is certainly intelligent (or at least, street smart), especially in The Lost Treasure of the Golden Squirrel when he decided to follow the penguins to find the treasure. However he is incredibly overconfident and that is likely his biggest weakness. He is greedy and not above playing as dirty as it takes to get what he wants.

Despite this, he willingly gave his throne to Mort in Rat Fink, saying "I'm just a guy whose good at punching stuff, I can't compete with the wisdom of the Great One." Mort being the Great One. This symbolizes that it is through superior strength, rather than intelligence, that the Rat King is in charge.