Guinea-Chairs

Guinea-chairs are what happens when Basaltine casts his CHAOS (in capital letters) spell.

                 CHAOS
 chairs  --------------------->  guinea pigs
          hellhoundish caster

Baskerville describes CHAOS as a spell designed to cause maximum panic and confusion. He's lying. It works on the assumption that a sudden influx of rodents tends to exacerbate any situation, and he only casts it when there are lots of women around in skirts.