Crocodillin

Crocodillin is an antibacterial substance found in crocodile blood. The active substance is a peptide isolated by Gill Diamond. Substance is presumably an explanation to how crocodiles are able to avoid serious infection in the very septic and contagious environment that they reside in.

References

1. Antibacterial properties of serum from the American alligator (Alligator mississippiensis), Merchant ME et.al., Comp Biochem Physiol B Biochem Mol Biol. 2003 Nov;136(3):505-13.
2. Naturally occurring antibacterial activities of avian and crocodile tissues, M. Shaharabany, et al, J Antimicrob Chemother 1999; 44: 416–418