Loser's Guide to Life
There doesn't seem to be much information about him in English. The French Wiki entry is here.
One fact that jumps out is that he is Louis Aragon's literary executor and, as it were, his heir. His relationship with Aragon was rather complex. Some would say Aragon was complex, but I would say he was a simple man whose simplicity provoked complexity in others. I think that's true of everyone.
Ristat wrote a longish poem called “Le Tombeau de Monsieur Aragon”.
He is noted (or perhaps feared) for the boldness of his enjambement: idéo/Gramme, etc.
But most important of all, he is the author of a book called N Y Meccano!