The humane society is setting the adoption fee for Giants-colored cats at just $9, reduced from the standard fee that ranges from $50 to $80, according to spokesman Scott Delucchi.
All adoptions include spay or neuter surgery, insertion of an identification microchip, all vaccinations and a health and behavior screening.
The Giants defeated the Atlanta Braves 3-2 on Monday to clinch the division series. San Francisco starts the National League Championship Series on Saturday in Philadelphia.
The humane society currently has more than 50 cats that are all black, partially black or orange in color, Delucchi said.
"We'll give a special gift to the adopter who comes up with the best Giants-themed name for their new cat or kitten," Delucchi said.
Pictures of some of the cats can be checked out at the PHS/SPCA website at www.phs-spca.org.
Adoption hours are Monday through Friday from 11 a.m. to 7 p.m. at the PHS/SPCA headquarters at 12 Airport Blvd. in San Mateo.
The special adoption offer will last until Oct. 31.