For me, it was a one two punch of horror comedy gold. Incidentally both Dekker entries also happen to be meta horror films that pay homage to a certain age of horror film; and offering a plot element that would become a trend later on, Dekker names his characters after famous horror figures like Romero, Cronenberg, Carpenter, etc. At the time it was a novelty. While "Monster Squad" was a love letter to Universal horror, "Night of the Creeps" is a call back to the Atomic age of horror with aliens and mutant slugs.
Much like "Return of the Living Dead," Dekker's film re-invents the zombie monster for a different twist on the tale, this time basing the zombie as more of an infectious parasite rather than a flesh eating beast. Starting in 1959, an alien ship accidentally unleashes a horde of parasitic slugs that escape the ship and crash land on Earth.