Secret Lair Drop

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.

Modern Horizons 3 Commander

Dark Depths enters the battlefield 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.

Dominaria Remastered

The List

Double Masters

Ultimate Masters

Ultimate Box Topper

From the Vault: Lore

Dark Depths enters the battlefield 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, put a legendary 20/20 black Avatar creature token with flying and indestructible named Marit Lage onto the battlefield.

Coldsnap

Dark Depths comes into play 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, put an indestructible legendary 20/20 black Avatar creature token with flying named Marit Lage into play.