Frankenstein's monster is seen
A pod is seen
The demonic baby
line "go ahead, make my day"
Just before Deborah Foreman drops the midget into the plant, the plant says "Feed me."
The missing posters reference Santa Carla, and are actually doctored from posters in that film.
The painting with moving eyes in Mr Throckmorton's house is the same as the portrait of Mark's grandfather in "Waxwork".
poster in daughter's room
The 'release' scene towards the end.
Erik Porn describes a scene featuring the werewolf from Waxwork.
The movie opens with the final scenes from Waxwork (1988).