A festively dressed British bulldog walks in a parade celebrating Christmas on December 23, 2017, in St Petersburg, Russia. (Photos: VCG)

Herman, an exotic shorthair famous due to his big eyes, wears an elf outfit and holds a red present in Copenhagen, Denmark, in December 2016.

A cat is festively dressed in Beijing on December 20, 2016.

Twelve dogs of a family in London are dressed in new outfits on November 16, 2014.

A baby lion and a baby tiger wear Santa Claus hats during a Christmas event at the Everland amusement park in Yongin, Seoul, South Korea, on December 23, 2014.

A tortoise wears its new shell suit — a giant Christmas tree. Katie Bradley, a tortoise enthusiast from Vancouver, Washington, has made 800 of the cute woolly suits for the shelled animals.

Four beluga whales wear Christmas hats during a show at Hakkeijima Sea Paradise Aquarium on November 18, 2006, in Yokohama, Japan.

Penguins wear Santa Claus and Christmas tree costumes during a festive event at the Everland amusement park in Yongin, Seoul, South Korea, on December 18, 2013.

Three chickens wear Christmas hats. (Compiled by Huang Jingjing)