OK... when I was little I watched this movie about rats or something that were in this dungeon thing and there was a hole in the floor with bars over it and the people [er... rats?] down there were all purple and either gooey or ghosty. The beginning has a view from above some rooftops... yep. And there was a young guy who was like.. the hero... and he wanted to save all the purple ones. Yeah I'd really like to know the name of this movie...

Second movie:
There was a large black woman that came to the house of these two boys. She was babysitting them or something. But they were really bad I think... so she told them stories about stuff... one had to do with indians [er... native americans.] and when she was telling the story arrows were shot all over the boys' room... she was a really mystically woman... yeah... I'd like to know the name of this one too... please!

Not sure about the first one,

But the second movie is a segment from "Amazing Stories" starring a very young Seth Green.