Wizkids Rules!

Molecule Man: Cheeseburger Eater
While Molecule Man is active, your Spider Friend characters cost 1 less to field, cost 1 less to purchase, and return to the field Zone after they deal combat damage to your opponent.

Rule 2.7.4.3.1 Each attacker that is unblocked will assign combat damage equal to its Attack value directly to the Inactive player (reducing that player’s Life total accordingly) and that attacker will move Out of Play before any other abilities would resolve. The only exceptions are abilities that may prevent, reduce, or redirect that attacker’s damage. This means that the unblocked attacker leaves the Attack (Field) Zone after all damage is calculated and assigned but before any “when a player takes combat damage” abilities or any other damage resolves. Hence, any “while active” ability this Character die has can no longer be applied and this unblocked attacker cannot be the target of any subsequent abilities.