Today is the anniversary of the death in 2004 of French animator René Laloux. Animation World Magazine has a retrospective on his life and work here.
He made several short films, including the following:
The Monkey's Teeth (1960):
Les Escargots (The Snails) (1965):
The Prisoner (1988):
His most famous feature length film is Fantastic Planet (1973), which won the Grand Prix at the 1973 Cannes Film Festival. There is a separate post on that film here.