Brachypelma vagans is a species of tarantula known commonly as the Mexican red rump or Mexican black velvet. It ranges predominantly in Mexico, but can be found as far south as Belize, El Salvador, and Guatemala. They are terrestrial, burrowing spiders. The reason for the name red rump is because of its distinctive red hairs on its abdomen. Like most tarantulas, they will eat anything they can overpower, which is usually insects, but small lizards and rodents may also be consumed. They can grow to a 5 inch leg span, with males typically being smaller and thinner than the females. They prefer scrubland habitats.
In 1996, Brachypelma vagans was discovered in the wild in St. Lucie County, Florida. It is now considered an established non-native species in that state, where it is thought to have been introduced through either accidental or intentional releases of specimens imported via the pet trade, although their numbers have been dwindling due to many B. vagans eating insects poisoned by pesticides.
B. vagans is frequently kept and bred in captivity. They feed readily on commercially available crickets, cockroaches and other insects of suitable size. They are typically docile, though they can be skittish and prone to releasing urticating hairs. Females are long-lived, potentially reaching 15 years of age.
In popular culture
In Traditional Mayan Medicine
The Ch'ol Maya consider these spiders to be positive; and use them medicinally. A hierbatero kills it, then crushes it, mixes it with spirit alcohol and strains out any irritating hairs with a traditional cloth. The beverage is is used for the treatment of "tarantula wind" the symptoms being chest pain coughing and asthma. The venom peptide GsMtx-4 is being investigated for the possible treatment of cardiac arrhythmia, muscular dystrophy and glioma. 
A juvenile B.vagans feeding on a mealworm
- Salima Machkour-M'Rabet, Yann Hénaut, Peter Winterton and Roberto Rojo (2011). "A case of zootherapy with the tarantula Brachypelma vagans Ausserer, 1875 in traditional medicine of the Chol Mayan ethnic group in Mexico". Journal of ethnobiology and ethno medicine.