The King of Rat Town is an on & off antagonist in the Nickelodeon series, The Penguins of Madagascar. He is a mutated sewer rat who lives in the sewer and is the leader of many other sewer rats. He is known both as "Rat King" and "King Rat".
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.
He is an outrageously muscular and tall Rat, with very short legs. He demonstrates his strength through challenging the penguins, to which he usually loses due to being outsmarted by the four of them. He demonstrates his strength upon first meeting the penguins by flexing his various muscles.