Doyen of Philippine exploitation Cirio Santiago does a version of 'Creature from the Black Lagoon' (though closer in quality to 'Octaman' and the lead character is introduced as Dr Essex which seems too obvious to be coincidence) with this quaint action /horror where local folklore meets scaly reality when a swamp creature emerges from the depths to cause chaos on a small Hawaiian resort village.
The acting is variable, but the rubber lizard suit is really something to behold. Steis and Witt ('Tropic of Cancer') are decent in lead roles (local Sheriff and visiting herpetologist respectively) and along with Banks playing the selfish resort manager, the trio does a pretty good impersonation of 'Jaws' (there's also a 'Jaws 2' moment which you don't want to miss for pure ham value). Supporting actress Huntly is a minor highlight playing a busty model with a massive ego and a nose full of candy who dreams of making it in the movies.
As for the uncredited stuntman who gets to inhabit the Gillman suit, it's a thankless role which was never going to end well despite good intentions.
Not great, not awful, just mediocre with very mild gore, brief topless nudity, a couple of gunfights and a tonne of explosions shot on the grassy banks of an overcast Philippine river-bend.