The Cave Crawler

When The Cave Crawler enters the battlefield, put a number of +0/+1 counters on it equal the number
of lands you control that can produce green or black mana.
Whenever you place a land that can produce green
or black mana, place one +0/+1 counter on The Cave Crawler.
{3}{b}{g}, {t}: Search your library for one basic swamp and basic forest, you may place one down, then shuffle.