Sidewinder is a nickname given to a pit-viper species, the Crotalus cerastes and a venomous viper species, the Bitis peringueyi, both of said species live in deserts, with the former having an unusual movement patterns and the latter being an ambush hunter. This is interesting if you consider sidewinder's unusual and hard to predict movements.
↑ 1.01.1Akame ga Kill! Zeromanga; Chapter 3, page 11
↑ 2.02.12.2Akame ga Kill! Zeromanga; Chapter 3, page 20