Sentry Bot - Fallout #24

Sentry Bot

Set: Fallout (PIP)
Collector Number: 24
Type: Artifact Creature — Robot
Rarity: Rare
Mana Value: 5.0

Flash
This spell costs {1} less to cast for each creature attacking you.
When this creature enters, you get {E} for each creature attacking you.
At the beginning of combat on your turn, you may pay {E}{E}{E}. If you do, put a +1/+1 counter on each creature you control.