How bad is it? It has one of the most laughable monsters ever created.
Should you see it? Yes. It's not perfect, but it has its moments.
This is one of those classic B-movies, like "The Brain from Planet Arous," that are beloved, despite their failings. In this, a native prince of a Pacific island returns from the dead as a walking tree. The rubber suited monster looks disgruntled, more than evil. There's a doctor and an anthropologist that are studying a plague or H-bomb fall-out; the two seem connected. Nothing really happens for the first half hour. There's a truly terrible British accent, some classic dud dialogue and maybe 15 minutes of rampage at the end. The monster's so slow and, well, wooden, that capturing people seems unlikely.