Honorable Mention: SON OF TARZAN (1920)

• film serial (silent)
• released 05/?/1920
• directed by Arthur J. Flaven and Harry Revier
• based on the Burroughs novel of the same name, the main character is actually Korak, Tarzan's son, though the old man does show up
• a National Film Producing Corporation production

CAST (boldface denotes characters directly lifted from the comic or source material)

Korak, Son of Tarzan  (Kamuela C. Searle)

Lord Greystoke / Tarzan  (P. Dempsey Tabler)

Meriem  (Manilla Martan)

Lady Greystoke / Jane  (Karla Schramm)

Ivan Paulovich  (Eugene Burr)

Sheik Amor Ben Khatour  (Frank Morrell)

My impressions:

Haven't seen it and, so the web tells me, the only version available is an indecipherable mess, chopped-down from the serial length to a short feature.