Ravenous Gigantotherium
Creature — Beast
Oracle Text
Devour 3 (As this creature enters, you may sacrifice any number of creatures. It enters with three times that many +1/+1 counters on it.)
When this creature enters, it deals X damage divided as you choose among up to X target creatures, where X is its power. Each of those creatures deals damage equal to its power to this creature.
Watch Out
This card uses a replacement effect ('as [it] enters' or 'enters with') to modify how the permanent enters. This is NOT a triggered ability — it can't be responded to, and effects like Panharmonicon or Torpor Orb don't affect it.
This card's ability triggers when it enters the battlefield, not when it's cast. Effects that double ETB triggers (like Panharmonicon) work here. Countering the spell prevents the creature from entering, so the ETB won't fire.