Cebuella pygmaea, commonly known as the Pygmy marmoset, is one of the world's smallest monkeys. Due to its diminutive size, this species is often referred to as a "thumb monkey" or a "pocket monkey." Other commonly used synonyms for Cebuella pygmaea include the dwarf monkey, the pygmy tamarin, the pygmy lion tamarin, and the little lion tamarin. These synonyms all reflect the small and adorable nature of this species, which is native to the rainforests of South America. Although tiny, the Pygmy marmoset is an important member of its ecosystem, playing a crucial role in seed dispersal and pollination.