Devour 2 (As this creature enters, you may sacrifice any number of creatures. It enters with twice that many +1/+1 counters on it.)At the beginning of your upkeep, create a 1/1 green Saproling creature token for each +1/+1 counter on this creature.
The number of Saproling tokens created by the triggered ability is based on the number of +1/+1 counters on Mycoloth, not on the number of creatures Mycoloth devoured. It doesn't matter where the +1/+1 counters came from.