In that tradition of Dungeons and Dragons, here is a truly cheesy monster to slow your players down.
Dire Slug
Level 6 Controller - Large
Speed:5
Initiative: +4
Str: 14
Con: 16
Dex: 19
Int: 12
Wis: 14
Cha: 8
HP: 72 (Bloodied at 36)
AC: 20
Fort: 18 Ref: 19 Wil: 17
Powers
Slam
Basic - AtWill...