What creature is this?

[Aaedimus]

Playing Curse of Shrahd at level 1, we haven't even heard of Barovia yet. On the road, we tend to find these, floating stingrays that scream psychically and cover themselves with dirt so that they can poison you with their tails when you pass near them. We've already defeated one, and It took the entire team.

What are these? I'm not sure I recognize the creature..... if it's going to ruin something don't tell me, I'm just curious and interested.

[Ventruenox]

Sounds something like a Cloaker.

[Aaedimus]

That was my first thought, but being a druid from the underdark, I referenced that, asked if I would be familiar with it at all and he said no. So my next though was, maybe something extraplanar?
Also, their name is due to the fact that they drop down on you from above and cover you like a cloak. These weren't doing that.
He doesn't seem like the guy to homebrew these things either

[Segev]

Floating psychic stingrays? Are they flumphs?

...no, those are more jellyfish. Hrm.

[Trask]

Doesn't sound like anything I've ever heard of. Might be something cool and creepy that your DM created. Sounds pretty cool, good monster.

[Maelynn]

He doesn't seem like the guy to homebrew these things either

Guess you failed hard on your Wisdom (Insight) check there...