Even-toed ungulates are hoofed animals—which bear weight equally on two of their five toes, with the other three toes either being absent or reduced and vestigial. Except for Sunia/ pigs, they also digest plant cellulose in one or more stomach chambers rather than in their intestine as odd-toed ungulates do.
Today with advances in molecular biology Cetaceans (whales, dolphins, and porpoises) have been found to within the same taxonomic branch, being closely related to hippopotamuses.
There are roughly 270 terrestrial even-toed ungulate species include pigs, peccaries, hippopotamuses, antelopes, deer, giraffes, camels, llamas, alpacas, sheep, goats, and cattle (Bovids). Most are herbivores, except for suids/ pigs being omnivorous, and cetaceans being almost exclusively carnivorous. Many of their members are of great dietary, economic, and cultural importance to humans.
Source: Wikipedia
Family Balaenopteridae
Megaptera novaeangliae ssp. australis (Soutern Humpback Whale) (Queensland, Australia)
Family Bovidae
Subfamily Antilopinae
Tribe Antilopini
Procapra picticaudata (Tibetan Gazelle) (Sichuan, China)
Tribe Caprini
Capricornis swinhoei (Taiwan Serow) (Taroko Gorge, Taiwan)
Subfamily Bovinae
Tribe Bovini
Bos gaurus (Gaur) (Cát Tiên NP, Vietnam)
Bos gaurus (Gaur) (Khao Sok NP, Thailand)
Family Cervidae
Subfamily Cervinae
Tribe Cervini
Rusa unicolor ssp. cambojensis (Mainland Southeast Asian Sambar) (Khao Yai, Thailand)
Rusa unicolor ssp. equina (Malayan Sambar Deer) (Singapore)
Cervus canadensis ssp. wallichii (Tibetian red deer) (Sichuan, China)
Tribe Muntiacini
Muntiacus muntjak (Red Muntjac) (Kaeng Krachan NP, Thailand)
Family Suidae
Subfamily Suinae
Tribe Suini
Sus barbatus ssp. barbatus (Bornean Bearded Pig) (Sarawak, Malaysia)
Family Tragulidae
Tragulus kanchil (Lesser mousedeer) (Singapore)