Gimcrack was a Lebensweltian.
He acted as Darlow's enforcer at the Introlnductions Escort Agency. He went along with the Eighth Doctor to Tent City. When the Doctor came in contact with Carmodi Litian, temporal energy was released which caused Darlow to be fused with his employees Gimcrack and Svadhisthana. The composite creature touched one of the Unnoticed, which threw them back thousands of years, eventually evolving into the Unnoticed. The Doctor called this temporal paradox a "predestination bubble". (PROSE: The Book of the Still)