When you encounter this phenomenon, starting with the next player in turn order, that player chooses a permanent type. The next player chooses a number between 1 and 10. The next player chooses a keyword counter. Then reveal and resolve the following ability with those words. (don't reveal the second ability before the words have been chosen!)
Each player creates a token that's a copy of a [permanent] and puts [number] +1/+1 counters on it. If it's not a creature, it becomes a 0/0 creature in addition to its other types. It enters with [keyword] counter.