What's that green thing?

Hint 1 of 4:

It's an alien.

Hint 2 of 4:

And it already killed everybody that was around here.

Hint 3 of 4:

And you are going to be the next one if you don't immobilize it quickly.

Hint 4 of 4:

Fortunately for you, it's possible to reset the timer.  This may be a bug,
but it does work.  Just return to the laser beam room, so now and then, if
you feel things are getting hot.