Who is Ignatius Small from The Cat Who Went Underground and what is their importance?

Ignatius Small, better known as Iggy, is the second builder Qwill hires to build his addition. He was recommended for the job by Gary Pratt. Iggy is described as an emaciated man with large teeth. He disappears while Qwill is hospitalized. After his discharge, Qwill finds Iggy buried in the crawlspace with Koko's help. Iggy was number five on Joanna's list.