Vorchex, The Unnatural

Indestructible, Trample
Vorchex is not a creature unless your devotion to
green is 6 or more.
Convoke (Each creature you tap while playing this spell reduces its cost by {1} or by one mana of that creature's color.)
Nature bleeding across the lines of plants and animals
has birthed antient abominations that are best not to be rediscovered