I built my tiefling warlock as an arachnomancer with the scorpion aspect. As part of her pact, she was "gifted" a scorpion's tail to replace her normal tiefling tail and this included a venomous barb. My question is how do I treat that as an attack? Is it considered a grapple and do I treat it the same as an attack from something similar, like a giant scorpion?
Would that be a combo attack/save for my target? The first one is a puncture wound from the barb and the second is envenomation.

Quote from Scorpionking60164 >>

I built my tiefling warlock as an arachnomancer with the scorpion aspect. As part of her pact, she was "gifted" a scorpion's tail to replace her normal tiefling tail and this included a venomous barb. My question is how do I treat that as an attack? Is it considered a grapple and do I treat it the same as an attack from something similar, like a giant scorpion?
Would that be a combo attack/save for my target? The first one is a puncture wound from the barb and the second is envenomation.

 If you are a player then the tail is just a tail. There are no attacks associated with it.

If you are a DM or your DM allows it, you can really do anything with it. Though I would base it on a giant scorpion.

This is presumably homebrew by your DM, so you're going to have to ask your DM how it works.

It's presumably a natural weapon, for which there's already extant rules.

(If you're just building the character outside a game, then without DM permission, it's just an unarmed attack.)