Monstroid - it Came From the Lake (1980)

What's Happening: Chemical spill creates giant reptile that attacks villagers in Columbia
Famous For: John Carradine plays a moustached priest, a.k.a. "Monster"
Carradine's priest has no bearing on the plot, but this grade-Z silliness is remembered also for featuring Robert Mitchum's son and for comprising a 1984 Elvira episode. It's slow and pointless, with little indication that anyone involved was trying to entertain the viewer. Either the camera or the video transfer is permanently shaky, so it's no fun to watch. A brief implied skinny dip and a brief implied burning-at-the-stake provide brief breaks from the tedium. Amateurish acting and pointless conversations are occasionally amusing. I should admit that the monster puppet isn't terrible, and we can see in some late scenes that they actually built more than just the head and one foot. Eventually they hook it like a fish and blow it up. Michael J. Weldon reports that parts of it were filmed years earlier.

Goldweber, David Elroy (2012-06-14). Claws & Saucers: Science Fiction, Horror, and Fantasy Film: A Complete Guide: 1902-1982 (Kindle Locations 50478-50498). David E. Goldweber. Kindle Edition.