Watermarsh Oak

When Watermarsh Oak enters the battlefield, you
gain 4 life.
{t}: Add {u}, {b}, {g}
{t}: Add {c}{c}
{t}, {g}{g}: Create a 1/1 elf token creature.
{t}, {b}{b}{b}: Create a 2/2 zombie token creature.
{t}, {u}{u}: Create a 1/1 merfolk token creature.