The Brazilian flea toad may be the world’s smallest vertebrate
Males measure about seven millimeters long on average

The Brazilian flea toad has nabbed the title of world’s smallest known amphibian and smallest known vertebrate. At just 7 millimeters long on average, the frogs are a fraction the size of a 27-millimeter-wide $1 Brazilian real coin.
W.H. Bolaños, I.R. Dias and M. Solé/Zoologica Scripta 2024