How bad is it? It's one of the lesser animals attack films.
Should you see it? If it shows up late at night on TV.
Toxic waste turns rattlesnakes extra-extra-deadly, rather than just deadly and that seems to be the excuse for them to behave like snakes never do. They bite through tires. They stalk people. It's hard to get a snake to act on command, so the attack scenes are all stagey. A woman takes a bath for no reason other than that makes for a cool attack scene. The guys investigating the case just head off to Las Vegas for no reason (all on film) and then come back - we apparently get to see their vacation video. It's too dull to be entertaining, and not bad enough to be entertaining.