Intelligent and good-natured centipedes, the Trell were naturally incapable of bad deeds, except when manipulated by, say, Morbius or the Eight Legs.

Podcast A013 Sisters of the Flame & Vengeance of Morbius > > > > >

The Doctor and Lucie battle bionic centipedes, face the Sisterhood of Karn, and must stop the regeneration of Morbius.