Navajo Skinwalkers

Navajo Skinwalkers may only activate one ability once per turn.
(G): Navajo Skinwalkers gets +1/+1 until the end of the turn. (G)(G): Navajo Skinwalkers gets +2/+2 until the end of the turn. (G)(G)(G): Navajo Skinwalkers gets +3/+3 until the end of the turn.
They call it a "yee naaldlooshii."