Udyr, the spirit walker

When Udyr, the spirit walker enters the battlefield, add {w},{b},{r} or {g} to your mana pool.
{w}: Transform Udyr, the spirit walker into Tiger form.
{b}: Transform Udyr, the spirit walker into Bear form.
{r}: Transform Udyr, the spirit walker into Phoenix form.
{g}: Transform Udyr, the spirit walker into Turtle form.