Anup Shah / Forest elephant herd (Loxodonta cyclotis) drinking and wallowing in a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic

Warwick Sloss / Hippotamus {Hippopotamus amphibius} large group wallowing in a drying river bed, Katavi National Park, Tanzania, December.

Nick Garbutt / Male Bearded Pig (Sus barbatus) at forest wallow. Bako NP, Sarawak, Borneo, Malaysia.

Chris O'Reilly / Red deer stag shaking off mud after wallowing {Cervus elaphus} Scotland, UK

LYNN M. STONE / Domestic pig wallowing in mud {Sus scrofa domestica} USA.

Jane Burton / African Clawed Toad (Xenopus laevis) emerging from mud, Africa.

Shin Yoshino / African Elephant (Loxodonta africana) along waterhole with wallowing Hippopotamuses (Hippopotamus amphibious) and Cattle Egret (Bubulcus ibis) flock, Ngorongoro Crater, Tanzania

Mitsuaki Iwago / Hippopotamus (Hippopotamus amphibius) mother wallowing with her young, Kenya

John Cancalosi / African elephants bathing {Loxodonta africana} South Africa

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pool on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pond on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi) wallowing in temporary rainy season pool, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador