I found this nice hi-res cover of Pilote magazine #140, Feb '86, presumably by Jean Solé, and now I’m left to name the characters. I’m pretty terrible at this, but here’s what I’ve got:

LEFT COLUMN (front to back):

1. LL, by Morris
2. Jill Bioskop, by Enki Bilal
3. Jack Palmer, by Pétillon
4. Jonathan Cartland, by Harlé & Blanc-Dumont
5. character from The Night, by Druillet
6. Isaac Newton, by Gotlib
7. Félina by Annie Goetzinger
8. Blueberry, by Moebius

RIGHT COLUMN (front to back):

1. Valerian, by Christin & Mézières
2. sheep from Le Génie des alpages, by F’Murr
3. Achille Talon, by “Greg”
4. Philémon, by “Fred”
5. Cellulite, by Bretecher
6. unknown character by Gérard Lauzier
7. Sir Francis Albany, by Floc’h

BOTTOM:

• Left: Le concombre masqué, by Mandryka
• Right: La coccinelle, by Gotlib

EDIT: bolded names are thanks to user input