That would make sense yeah, a lot of fun things got salvaged from 4e in some form or another

I believe it was the 5e beholder with some alternative options from Volo’s Guide to Monsters back when that book was new

I tpk’d a party (except a couple who ran away) with a special ice beholder when they entered its lair on the plane of ice
a lot of sliding involved and the beholder taking advantage of levitation to avoid its own frictionless floor
It was a very meat-grinder-y campaign so it was okay and mostly fair

Possibly interested depending what you have in mind, pretty experienced GM and player. Though I imagine you might be getting pretty full up on people 😅