As a kid i remember seeing this one movie with an asian guy and his son living in poverty. The kid goes to this rich-kid school because his father doesn't want him to end up like him, the son's "friend" has this weird robot dog toy and the son REALLY wants it for some reason. Then somehow he finds a weird green creature that looks like this

He names it after the robot dog it really wants and hjinks happen and the creature DIES AT THE END???? but apparently he had friends and now there is a whole bunch of these creatures.