Lil' Slugger is the boss of The Forest. It is a giant chainsaw with legs controlled by Dr. Fetus. The original design was a large metallic spider, but it was later changed. In an earlier version of Lil' Slugger, to defeat it, you had to throw squirrels that comes from a mountain in way to kill it. When a squirrel hit the boss, it would glow white, red, and yellow. In the current version of Lil'Slugger, Bandage Girl is tied to the back of the machine. In the earlier version, she appears to be standing on the cockpit.
Lil' Slugger's level is essentially an obstacle course. It is a horizontal level with Lil' Slugger pursuing Meat Boy. You must run through saws while avoiding Lil' Slugger. Sprinting is essential for this level as if you don't run fast enough, Lil' Slugger will catch up to you. At the end of the level, you jump up into the small cave at the top, causing Lil' Slugger to crash into the wall and break down. A strategy is to touch the cave and not get on top of it. Meat Boy does not die in this way.