The Abominable Snowman from Half Human isn't the scariest of all the terrifying kaiju out there; he's essentially Toho's version of King Kong before they had a version of it.
In the first, Revenge of the Creature (which also starred a very, very young Clint Eastwood), the story was essentially remade to conclude with him outside of the lagoon.
Frankenstein Conquers the World is entertaining for people who can appreciate Japanese kaiju movies from the 1950s, 1960s, and 1970s.
However, it's obviously a B-movie and one of the pioneering ones at that. Nothing is less frightening than a rabbit, and the film does a terrible job of conveying it. However, that's part of its attractiveness.
Though it has a devoted following, C.H.U.D., one of the greatest cult creature features of the 1980s, has largely been forgotten over time. Which is weird, because it's incredibly creative and even has an A-list cast
Australia's Jaws is called Razorback, and to be honest, it's far superior than most American attempts to recreate the hit movie's popularity.
Sean S. Cunningham, the director of Friday the 13th, attempted to replicate his success by doing it better, but was unsuccessful.