Menace (This creature can’t be blocked except by two or more creatures.)
Whenever another creature you control with power 2 or less enters, you may discard a card. If you do, draw a card. Do this only once each turn.
Irreverent Gremlin's second ability checks the power of the other creature only at the moment that creature enters. If a creature enters with counters, those counters are included. If a creature's power is 2 or less when it enters but becomes greater than 2 while Irreverent Gremlin's second ability is still on the stack, you'll still have the choice to discard a card when the ability resolves.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.