text: Watchful Radstag “evolves” when its evolve ability resolves and a +1/+1 counter is put on it. If a replacement effect causes the evolve ability to put more than one +1/+1 counter on Watchful Radstag, its last ability triggers only once. If no +1/+1 counter is put on it (perhaps because it left the battlefield while its evolve ability was still on the stack), then its last ability doesn’t trigger.