Sideshow Mel replaced Sideshow Bob after his incarceration as Krusty the Klown's assistant.  Sideshow Mel, born Melvin Van Horne,  is voiced by Dan Castellaneta.

Sideshow Mel Quotes

Sideshow Mel: Bleh! There's cheese in this sandwich! Surely you know I'm lactose intolerant!
Bart: Sorry.
Sideshow Mel: Sorry? Do you know how sick this is going to make me? Come stand next to the bathroom door, I want to yell at you some more.

Groundskeeper Willie: Come on ya pansies, I've seen fiercer fights in parliament
Sideshow Mel: What is this, prime minister's question time?

The Simpsons Quotes

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!

Mr. Burns: Men, there's a little crippled boy sitting in a hospital who wants you to win this game. I know because I crippled him myself to inspire you.
Milhouse: (to his mom and dad) I hope they win, or Mr. Burns said he's coming back.