Also spelled "creotoxin". This is a term for any basic (pH over 7) toxin produced by bacteria or fungi in spoiled meat.
For instance, creotoxin B.T.X-A acts as a strong muscle relaxant. It can block the release and uptake of acetylcholine, and thus partly block the transmission of nerve signals to muscles. People who have been poisoned with this toxin suffer from paralysis and a lack of muscle tone.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.