The Gastric Brooding Frog

"The gastric-brooding frogs or Platypus frogs (Rheobatrachus) were a genus of ground-dwelling frogs native to Queensland in eastern Australia. The genus consisted of only two species, both of which became extinct in the mid-1980s. The genus was unique because it contained the only two known frog species that incubated the prejuvenile stages of their offspring in the stomach of the mother."

via bioephemera