Dogs in costume

A dog in costume as a NYC MTA bus during the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011. The parade of masquerading dogs is the largest Halloween dog parade in the U.S.

A pet owner checks the costume of her pet Chihuahua during the Philippine Animal Welfare Society's (PAWS) annual Halloween fund raising event entitled "Scaredy Cats and Dogs: Year 8" at the Eastwood Central Plaza in Manila on Oct. 23, 2011.

Sarah Polgee and Kiki pose during the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

A dog in costume during the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011. The parade of masquerading dogs is the largest Halloween dog parade in the U.S.

Gina and Scott Keatley with Buttercup as Popeye and Olive during the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

A dog as a pin cushion the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Jack dressed up as Don Draper from "Mad Men" during the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Karen Biehl and Eli attend the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Jazz the Aircraft Carrier and crew attend the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

A dog dressed as New York City fire truck attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

An Occupy Wall Street dog attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Shaggy the New York Yankees dog attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

A dog dressed as Hurricane Irene attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

A dog dressed as a sightseeing bus attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Two Chihuahuas wait for their turn in a competition during the ExpoCan show in Mexico City on Sept. 17, 2011.

Tank the English Bulldog dresses up as a runaway bride and attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

The "Avatar" dog attends the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

Summer Strand and "Princess" Beatrice attend the 21st Annual Tompkins Square Halloween Dog Parade in New York on Oct. 22, 2011.

CBS News 24/7