Jack Arnold's last sci-fi horror for Universal isn't as good or as much fun as most of his previous efforts (including the oft-overlooked "Tarantula") but it has its own virtues to recommend it. The story is a clone of "I Was a Teenage Werewolf" -- except that in this case, we have a college professor who keeps accidentally coming into contact with chemical agents which transform him into an aboriginal "throwback."
Not much killing, or action at all for that matter, and in retrospect the film's manner in general is too straight and serious for its flimsy materials. Not much sympathy or interest is generated before the film runs its course, but an audience may get a few laughs from some of the stilted dialogue and from the oversized "throwback" creatures that appear from time to time to terrorize unsuspecting coeds and jocks.
The female lead was written to have a very unappealing personality -- for one thing, when the scientist she supposedly loves is getting really interested in his work, she goes over his head to his boss (who "happens" to be her father) to have him investigated for insanity! Maybe he just wasn't paying enough attention to her.... anyway, I don't think many in the audience would have minded if she HAD gotten hers from the monster in the end....