Brazilian Yellow Scorpion

Adult specimens typically measure between 5–7 cm (2–3 in) in length. As suggested by its common name, coloration consists of pale-yellow legs (8 in total) and pedipalps, with a darker shade of yellowish brown on the trunk and tip of the legs, pedipalps and tail. Like other members of the family Buthidae, T. serrulatus has a bulbous tail, often carried in a characteristic forward curve over the back, which is segmented, with prominent ridges and serrations. The tail is tipped with a venom-injecting barb capable of immobilizing prey or delivering defensive strikes.

The species is endemic to Brazil and widely found throughout the country, including the states of Alagoas, Bahia, Ceará, Espírito Santo, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Pernambuco, Rio de Janeiro, Rio Grande do Norte, Rio Grande do Sul, Rondônia, Santa Catarina, São Paulo, Sergipe, and Distrito Federal. "Due to deforestation and growing urbanization, this species is becoming more and more present," according to Rogério Bertani in an interview with the British newspaper The Guardian. He is a scientist and scorpion specialist at the Butantan Institute in São Paulo. "I personally think that the problem will continue to grow." By 2018 there was a notable increase in the number of T. serrulatus scorpions living in the urban spaces of São Paulo, contributing to an increase in reported scorpion stings in Brazil from 12,000 in 2000 to 140,000 by 2018. An abundance of prey, notably cockroaches, and shelter along with a lack of predators is believed to be a cause of the increase in scorpion numbers in Brazilian cities.

It has a diet of insects, such as cockroaches, and is suited to life in sewers and trash heaps in urban areas. Having a low metabolic rate, it can survive for months without eating.