In case you want to add the coloring book appearances as red appearances, here they are:

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Elan: 11
Roy: 9
Belkar: 7
Durkon: 7
Vaarsuvius: 7
Haley: 6
Mr. Scruffy: 4
Celia: 3
Nale: 3
Redcloak: 3
Thog: 3
Xykon: 3
Banjo: 2
Blackwing: 2
Giggles: 2
Ancient Black Dragon: 1
Monster in the Darkness: 1
Thor: 1
Young Adult Black Dragon: 1
Hobgoblin A: 1
Hobgoblin B: 1
Hobgoblin C: 1
Hobgoblin D: 1
Hobgoblin E: 1 (The answers page implies those are their names)

And I think we don't count the cover pages, but if we do:
Elan: +3
Belkar: +2
Roy: +2
Demon-roaches: +1
Durkon: +1
Haley: +1
Monster in the Darkness: +1
Mr. Scruffy: +1
Nale: +1
Thog: +1
Vaarsuvius: +1