There are two bands called "The Mammals".
1. A Japanese Blues- and Indie-Rock band, also called マンマルズ. Their first album "WoO!!!" has been released on May 22nd, 2013. Their sound is a fusion of Motown, Brit Beat, Garage, Reagge and Rock n Roll.
2. An American band connecting rock and traditional Appalachian music.
They travel America in a large diesel van filled with drums, amps, an upright bass, fiddle, guitars and banjos. They have crafted a show that connects rock and traditional Appalachian music in a very organic way. Read more on Last.fm