You can do this any time you could cast an instant.
It's something I wish The Pokmon Company would do for every set, seeing as they're that rare it doesn't effect the raw value of single cards on the secondary market
This causes the cards to appear backwards upon opening the pack, reversing their reveal order and needing you to turn them over too
Urza does a ton, creating a creature token, generating mana, and giving you free cards which is just incredible
It does get a little better with Rat tokens, but Id still steer clear of it most of the time Giving up food to hurt your opponent can definitely have a place, and even be a win condition, and the base line of the card as a three mana 3/2 that makes a food isnt a disaster Even without the enchantment part, youd always play it in your black decks
If you put a fifth counter on it some other way, it won't be immediately sacrificed