Finnish graphic artist Jaakko Seppälä created this masterpiece about a decade ago, simulating ten famous cartoonists drawing the others’ characters. Starting from the upper left and working down-and-right diagonally, we have:

• Astérix, by Albert Uderzo (France)
• Calvin, by Bill Watterson (USA)
• Donald Duck, by Carl Barks (USA)
• Captain Haddock, by Hergé (Belgique)
• Batman, by Bill Finger & Bob Kane (USA)
• Fingerpori, by Pertti Jarla (Finland)
• Corto Maltese, by Hugo Pratt (Italy)
• Moomin, by Tove Jansson (Sweden-Finland)
• Garfield, by Jim Davis (USA)
• Lucy Van Pelt, by Charles Schulz (USA)

WP has some basic info for him: (turn on translate)
https://fi.wikipedia.org/wiki/Jaakko_Seppälä_(graafikko)