What was the craziest cartoon(s) you saw whilst a kid?

The first one that comes to mind is this one from probably the early 90s. From what I remember it was a group of kids and one of them is sick or something and the other kids try to save him? In the end they each sacrifice a year of their life so that the sick friend can live. I wanna say Steven Spielberg was a producer.

There was also that one crossover movie where a bunch of cartoon characters from whatever was popular in the 80s did an anti-drug movie.