Stegron the Dinosaur Man

Discard clauses like this one turn a card into a fork in the road: either you cast the 5/4 menace body and get a hard-to-block threat, or you spend the card from hand to pump and re-type something already in play. Most pump effects want the source on the battlefield, banking on repeated activations; the Dinosaur Formula ability instead cashes the whole card for a single +3/+1 swing that also stamps the target as a Dinosaur. That type rider is the tell about what this serves. On its own, "becomes a Dinosaur" does nothing; alongside payoffs that reward the type (anthems, cost reducers, triggers that count Dinosaurs), it converts any creature you control into fuel, then feeds itself to the graveyard. The seam between the two modes is what makes the design honest: the discard ability lives in your hand, so once you resolve the creature it can no longer enable anything. You commit to one use or the other, and neither is the automatic line. That runs against the usual instinct with a five-drop, which is to treat the printed body as the default and everything else as upside. Here the cast is never free of opportunity cost, because casting is the choice that closes the other door. The card stays genuinely open every turn it is in hand, and the value of the 5/4 depends entirely on whether you have a better creature to point the formula at.