Pantlaza, Sun Favored

Whenever Pantlaza, Sun- Favored or another
Dinosaur enters battlefield under your control,
you may discover X, where X is that creatures 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 it a random order.)