The landfall deck might like this, provided it's of the
Tatyova, Benthic Druid variant, and not the
Plated Geopede variant. Spells matters deck might or might not be interested in this card.
Young Pyromancer/
Guttersnipe decks try to land the synergy creature early, then go to town with spell triggers. Pearl Lake Ancient doesn't really work in that shell, because it's way too expensive. Typically you would have cast most of the spells in your hand before this lands. On the other hand, if the spells matter deck is more of a slow affair, stalling the game and using, for example,
Rise from the Tides as an eventual means to win, Pearl Lake Ancient might actually fit there. Where this shines most is in slow control decks that need a reliable finisher that doesn't just roll over and die to a single
Doom Blade. Another option in this category is
Sphinx of Jwar Isle, which is especially nice if you support top of library shenanigans obviously.