In 5e, I realize that you can not grapple as an opportunity attack, as the grapple is an action and the opportunity attack is a reaction.
However, am I correct in assuming that some monsters can grapple as an OA?
You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature.
Let's use a Vampire Spawn as an example. Listed in its attacks is using its claws:
Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (2d4 + 3) slashing damage. Instead of dealing damage, the vampire can grapple the target (escape DC 13).
Since the claws are considered a melee attack and they have this extra ability to grapple instead of deal damage, I would think they could be used for an AoO.
Just wanted to see if anyone can point out something I may have missed. Thanks!