An area classic, and a good tick for any boulderer, regardless of ability. Bum Boy features an array of layered slopers, each as tricky to use as the next. Compression and footwork are key. Start in underclings at the low horizontal break. From here, follow the groove up (someone will shout beta at you, but everyone figures out their own) and top out on a good sloper to the left.
The grade is height-dependent. Probably V4 for a short person and lower for a tall.
Location
On the left side of the obvious Millipede boulder, right in the middle of the central maze of Horse Pens. Hard to miss.