Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Lumbering Megasloth

This spell costs {1} less to cast for each counter among players and permanents.
Trample
Lumbering Megasloth enters tapped.

Dark Depths

Dark Depths enters with ten ice counters on it.
{3}: Remove an ice counter from Dark Depths.
When Dark Depths has no ice counters on it, sacrifice it. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Sowing Mycospawn

Devoid (This card has no color.)
Kicker {1}{C} (You may pay an additional {1}{C} as you cast this spell.)
When you cast this spell, search your library for a land card, put it onto the battlefield, then shuffle.
When you cast this spell, if it was kicked, exile target land.