Normally, for things like this, the studio has rights to the actor's
likeness. For other aspects of merchandising, like actual figures of the
actor, there is a percentage given.

Unfortunately, many studios take advantage of the idea that there is no
such thing as a percentage of the net, since there is never (on the books) any
profit. Case in point: in the 27+ years of Star Trek, the majority of the big
seven actors have gotten about $16,000 from all of the dolls, figurines, chess
sets and zillion other products with their faces. This out of a billion
dollar franchise.

jms