In the film Ernest Goes to Camp when the Cheif was speaking seems to have been using real Plains Indian Sign Language based on the Wikipedia article for the mov
zorba-the-greek
doom-patrol
rizzoli-and-isles
the-wild-bunch
law-abiding-citizen
the-drop
terra-nova
talk-to-her
wild-hogs
terriers
get-smart-2008
dhadak
single-parents
star-trek-v-the-final-frontier
cloudy-with-a-chance-of-meatballs-2
braindead
videodrome
moonshiner
rush
gotham
i-care-a-lot
allegiant
pumping-iron
demolition-man
holmes-and-watson
three-colors-white
knight-and-day
maze-runner-the-scorch-trials
orgazmo
shaktimaan