African clawed frog
The magainins are a class of antimicrobial peptides found in the African clawed frog ("Xenopus laevis"). The peptides are cationic, generally lack a stable conformation in water but form amphipathic α-helix in membranes; their mechanism against micro-organisms is unclear but they disrupt the cell membranes of a broad spectrum of bacteria, protozoa, and fungi.