Grommid
From Archon Arcana
Grommid • Mars • Creature • Rare • You cannot play creatures.
After an enemy creature is destroyed fighting Grommid, your opponent loses 1. • Artist: Gong Studios • Card Number: CotA (194), AoA (197)
Commentary
Regardless if Grommid was the attacker in a fight, if Grommid survives a fight, its ability will resolve.
Source: Timing Chart•Fight
Cards put into play by another card's effect (rather than being played from an out-of-play area such as the hand or discard pile) are not considered "played" cards. If an ability “puts” a card “into play,” bonus icons and “Play:” abilities on the card put into play do not resolve.
Source: Play: (ability)
FFG has clarified that Grommid's "You cannot play creatures." ability should be treated as a constant ability that is active only while Grommid is in play rather than a play restriction that would be active in the hand.
Source