I remember this animated movie about these two kids whose grandmother comes to visit. The kids think the grandma is acting strangely and it turns out the grandma is a robot. One scene is of them in a grocery store and the grandma rips open boxes of cereal and ends up buying a bunch of motor oil. The kids see her later drinking it and eating rocks. Anyone know it?

Hi, there is a movie from 1982 called The Electric Gandmother, but its not animated so I don't know if that's what your looking for or not lol it prob isn't but I tried :) hehe good luck!!