Any of 276's (RIP in Peace) "rotary walker" bots.
Talk about a slasher - this guy would (inadvertently) climb on top of other robots and rip and rend their innards to pieces.
Back in the day, I believe FIRST used a video of their biggest rotary walker (I think it was their 2003 robot) climbing on top of another robot as part of some promo video. I believe they called that robot "Goliath".
I'm not sure if this was their largest iteration:
(Koko Ed likes this. He loves him some Mad Cows.)