Klahka, Spirit of Naya

Klahka, Spirit of Naya enters the battlefield tapped.
{t}: Add {w}, {r}, or {g} to your mana pool.
Whenever you attack with a white, red and a green creature, Klahka, Spirit of Naya turns into an 8/8 creature until end of turn that is white, red, and green and has trample.