Crystalline Crawler and Mindless Automaton have at least one +1/+1 counter on them.
({B} magic symbol) ({B} magic symbol) available.
Steps
Activate Yawgmoth's second ability by paying ({B} magic symbol) ({B} magic symbol) and discarding a card, causing you to put two +1/+1 counters on Crystalline Crawler and Mindless Automaton.
Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding ({B} magic symbol) ({B} magic symbol) .
Activate Mindless Automaton's second ability by removing two +1/+1 counters from it, causing you to draw a card.