As part of its ongoing efforts to promote every single Pokémon out there, The Pokémon Company has shared special content dedicated to Galarian Corsola:
Watch your step when wandering areas oceans once covered. What looks like a stone could be this Pokémon, and it will curse you if you kick it. Sudden climate change wiped out this ancient kind of Corsola. This Pokémon absorbs others’ life-force through its branches.
Source: @Pokemon