Mundo is one of the best champions in the game lol. His E at level 5 gives you like 100 damage + more depending on your health.
eta: Shocking damage at first 3 levels, nobody expects 25% of their health gone in one hit. One of the fastest clears in the game, I can kill both red and blue and still get to their red on time to kill the enemy jungler if it's an amumu or warwick (any character which waits for smite to kill 2nd buff).