It doesn't seem to be, though it may simply broadcast its emotions with body language humans aren't trained to parse.

[A lot of alien creatures do that. Hell, a lot of native Earth animals do that!]

It hasn't attacked me or displayed any aggressive behavior, so I doubt it's angry, but I don't know why it might be scared.

[It's not like he's a six foot tall brick of a man who could probably crack a coconut on his jawline.]