When I was a kid (grade school, in the 80s) my mom rented me lots of fantasy movies that she obviously hadn’t seen first–movies I hadn’t even asked to see–she just rented them to keep me occupied. Here’s the one I’m trying to remember:
In color. Saw it on VHS, probably between 1985 and 1988. Pretty sure it was actually made in the 80s. Had the same typical 80s fantasy movie aesthetic as movies like DRAGONSLAYER, KRULL, WILLOW, LADYHAWKE etc. In color. The general contours of the plot were pretty typical, too: a boy swept up in a quest with an old man/wizard type as a mentor.
One scene in particular has stuck with me and is the reason I want to figure out what this movie is: The boy is journeying along and then encounters the evil villain, a seductive woman, who pretends to offer him hospitality. She coaxes the boy into a hammock, climbs on top of him, being very sexy-like, then turns herself into a giant bug to eat (?) him. At the critical moment, the boy stabs his sword upward into her/the bug’s underside.
Another peculiar element of the movie may be that it is in the genre of normal children being sucked from the “real” world into some fantasy world to fulfill some quest, but my memory is not clear on this point. That much could be a different movie entirely.