They look kind of disconnected, honestly! Instead of just some circles, try remaking those studs to instead be worked into the shading.

I believe there are onionskin options in photoshop, a feature where previous and antecedent frames are added to the current frame as transparencies to better keep track of motions. See if you can find some documentation on that, it's probably one of the best tools a new animator can have to make eyeballing this stuff easier to figure out.

If not, aseprite is ten bucks and I've been using it for all my animation work since I got it. It's threadbare right now animationways but it's got enough to make little loops and sprite sequences, which is what you're doing here.

So it's a "the monster noticed you" animation?
It might be helpful to look at how other games tackled that, I know some of the animations the Alien makes in Alien: Isolation are pretty good, it might be wise to look at some youtube footage and take cues from that!
Other things to note would be footage of predatory animals and how they react during hunts.

Can you provide a source on that? sounds like something worth reading about, but I also have a policy of not taking gossip at face value.