Made in 1958, here is a general reworking of all the came before. It's Dr. Jekyll/Mr. Hyde married to any werewolf movie. Yet, it never entirely verges into camp or silliness. The performances are strong, even from the dog. The music, though borrowed from other movies like 'The Incredible Shrinking Man' and 'Tarantula', is used effectively giving the action a boost where needed.
The special effects were nothing special. The transformation from man to beast and back again were smoother than 'The Wolfman', but the resulting creature was almost too obviously a rubber mask. Closeups do kill the effect somewhat so they filmed him at a distance which pulled the visuals back into plausibility. Much of it works well.
But why was this made? As noted, there's nothing new. It is played as a very straight forward no nonsense monster movie. It has its moments of real horror but it also doesn't even try push boundaries. If you had to judge it against all other of this genre, it's a C+.
A good solid movie for a rainy day and popcorn.