Devouring Bog

Devouring Bog enters with 2 charge counters. When all charge counters are removed from this, exile it, and shuffle it back into its owner’s library at the next end step.

{1}{t}: Add {b} to your mana pool. Place a charge counter
on Devouring Bog.

Remove all charge counters from Devouring Bog, {t}: Add {b} to your mana pool for each charge counter removed.

What you can find in the depths of the bog is not as concerning as what can find you