Oracle of Mul Daya 7.5 The big Explore
You toss on counter on this when it deals damage, not two, but you can untap a land to make mana, force a target dork to not block, or toss a +1/+1 counter to perma-pump the equipped dork
Despite that, hes got an ability that makes him incredibly powerful
Rather than losing just a part of the top like the Elementalist above, there have been cases where the card is simply demolished by the booster gods, giving a deep crimp on two separate halves of the card before it is sliced and the pieces are sealed into different boosters
Plus, the recessed handle makes it easy to carry to tournaments, game nights, or anywhere your deck boxes need to go
The most traditional or old school Rat that was known for doing this was Ravenous Rats