Slash, Elite Tracker

Whenever Slash, Elite Tracker or another Dinosaur you control enters, you may discover
X, where X is that creature's toughness.
Do this only once each turn. (Exile cards from
the top of your library until you exile a
nonland card with that mana value or less.
Cast it without paying its mana cost or put it
into your hand. Put the rest on the bottom in a random order.) Pantlaza, Sun-Favored