put on
They tied him up and put a gag on him.

remove, take off

funny, good, great
the movie's best gags

cheap, lame
old
obvious
gross-out (AmE,informal)
sight, visual
a mixture of wit and instant visual gags

running
There was this running gag about a penguin.

crack (BrE), tell
a non-stop comedian, telling gags by the dozen

write

gag about