Without Warning (1980)

A low budget sci-fi/horror that used half of its entire budget to hire Jack Palance and Martin Landau; neither man phoned it in, but both are unlikely to have placed it high up on their CV. It was also Ralph Meeker's last role.
The plot is thin. It's hunting season at the lake, but the wildlife isn't the only thing being taken out - an alien presence is culling the human population.
The actual alien is embarrassing (when it does eventually appear), but his flying, fleshy, yellow pus-filled pancakes are fantastically bad-good.
The best of the rest of the cast is the young woman playing Sandy, namely Tarah Nutter. A quick trip to IMDB proves that it didn't happen, but Tarah probably deserved to have a decent B-Movie career thereafter.

1½ free lumberjack shirts out of 5