Extraplanar being

Convoke (Your creatures can help cast this spell.
Each creature you tap whilst casting this spell pays for {1} or one mana of that creature's colour.)
Flying, hexproof, protection from green

When Extraplanar being enters the battlefield,
tap all green mana. They don't untap during
their controller's next untap step.

Beings from beyond the planes don't tend to listen to
the laws of nature.