Return up to two target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a deathtouch counter on either of them. Then put a menace counter on either of them.
If a card in a player’s graveyard has {X} in its mana cost, X is considered to be 0.
If you return no creature cards to the battlefield, you won’t put any counters on any creatures.
If you return two creature cards, you may put one counter on each or put both counters on one.
You could target a single creature card with Call of the Death-Dweller. In this case, you’ll put both counters on that creature.