Smart-shroom

The Smart-shroom is a mushroom, so it's only awake during the night. A Coffee Bean is necessary to wake it up in day levels.

It shoots spores that have a 15% chance of hitting a zombie critically, dealing 3 damage instead of 1, but it hides and stops shooting when a zombie is in a 3x3 space around it.

Strategy
Place Smart-shroom behind other plants to hinder its ability to get scared and hide.