The Vulture (1967 UK/Canada)

This comes across as a horror film, but the creation of the titular monster is via "nuclear transmutation," a theory forwarded by the newly-arrived hero-scientist (Robert Hutton), who deduces all this with basically no evidence. But, he's right - some local mad scientist has indeed grafted himself with a dead vulture by means of highly radical, advanced scientific wizardry and is terrorizing the local rural area. He has only three actual targets - the descendants of the family which buried the villain's ancestor alive. I guess he really knows how to carry a grudge. The whole premise and the plot are quite absurd, but it's somehow compelling, especially for kids, who may find it very creepy - including the prototypical eerie music score.
Some of this reminded me of  Island of Terror (66) - it has the same theme of science going way out of control, with horrifying results, and a similar setting; it's not as good, has quite a few slow spots and lacks a superior cast (though Akim Tamiroff is pretty good). Broderick Crawford sort of walks his way through this. The climax is a bit baffling: the hero is unable to convince any of the authorities of what is really going on - no surprise there - but he takes it upon himself to dispose of all the evidence after the threat is over, probably because the truth is too terrifying to make public. This assures that the coppers will never know the facts - why this supposed hero makes this judgment call may be a critique of all modern scientists.  BoG's Score: 6.5 out of 10.