Spaw is a professor of medieval poetry in real life.
Bobert is an astrophysicist.
Sir jOhn from HuLL is a retired cultural attache.
Leeneia is a former Miss Wisconsin.
Amos in a captain the Mounties.

If you read the Mudcat long enough, you will catch these and others shifting in and out of various personas. Spaw, for example, has entered a rational period.