Opportunistic Dragon
Creature — Dragon
Oracle Text
Flying
When this creature enters, choose target Human or artifact an opponent controls. For as long as this creature remains on the battlefield, gain control of that permanent, it loses all abilities, and it can't attack or block.
Watch Out
This card involves continuous effects applied in layer order. Type changes (layer 4) are applied before ability changes (layer 6) and P/T changes (layer 7). The order matters — a creature that loses abilities in layer 6 can still get new abilities from effects applied later in the same layer.
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.