Weasles

A disease mentioned by Pestilence as something he looks forward to observing. When the Angel of the Iron Book asked if he was talking about measles, Pestilence replied gloomily that he definetely said weasles. People are getting really careless with this new business of bio-artificing. We are talking about boils that really bite.

Presumably communicable by walrus.

Note the spelling as opposed to weasel, a mammal.

Annotation

A horribly dangerous evolution of the Roundworld disease measles; In fact, it could possibly be some Igor's attempt to blend measles and weasels.