The Mongolian toad, also known as the piebald toad or Siberian sand toad, is a species of toad found in East Asia. It ranges through much of China, Mongolia, and the Russian Far East, and is also found in the northern Korean Peninsula. According to Kuzmin et al., it is not definitely known to be present in South Korea. It is particularly common in the Amur River basin of China and Russia.
The Mongolian toad is relatively small, with adults not exceeding 9 cm in length. It ranges through a wide range of habitats is often found in dry regions, preferring sandy soil; it was first described based on specimens from the Alashan desert. The species does not occur above 2700 m, or below 600 m. The northernmost population is found on Olkhon Island in Russia's Lake Baikal.
The mating season occurs between March and July, depending on the local climate; eggs are typically laid in shallow puddles, leading to the death of many tadpoles as the puddles dry up. Mongolian toads hibernate in the ground, usually in groups, in holes up to 2 metres deep. Adult toads favour ants as food, particularly in arid regions; they also eat spiders and beetles.
The Mongolian toad was classed as Bufo raddei prior to the 2006 definition of the genus Pseudepidalea. Other closely related species include the European green toad, Pseudepidale viridis.