[LittleBillyInfidel]

I think that was Joe Dante, who did GREMLINS. Spielberg did the rest home segment.

[Dr. Sivana]

I think that was Joe Dante, who did GREMLINS.
You are right. Spielberg oversaw the project, but Dante did the directing on the segment. Wikipedia credits Richard Matheson for the screenplay. Sad, because he's done other solid work. His (and Dante's) ending is the opposite, and I am just waiting for the sequel when Anthony Freemont gets mad at Helen just once, and turn her into a puddle of pancake syrup that he eats.

A TV series reboot from a few years back treated it better, with Mumy being a 40 something Anthony Freemont in this town where little has changed, except that he has a daughter (her mom? who knows!)