Predator type cryptids

My wife and daughter swear that while driving home earlier this week that they both saw something like a "invisible" predator off the road about 15 feet in some woods. They say that it looked like an upper adomen, and then two big arms that were like a sort of mirage or something. Apparently it was enough of a sighting that they were very animate and excited in describing it when they came home. I describe it as a predator cryptid as I have no other definition I can think of.

Wish I would have been with them as I have never seen anything that weird.

Also, if this matters, neither of them are really interested in that kind of thing.