Swarm Shambler [Zendikar Rising Prerelease Promos]

Swarm Shambler enters the battlefield with a +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it becomes the target of a spell an opponent controls, create a 1/1 green Insect creature token.
1, T: Put a +1/+1 counter on Swarm Shambler.