I only found this out today, having stumbled across Simon McBurney's tribute to him on the WOS news page.

I remember KC from the 70s onwards in TV appearances but my fondest memories are from some of his one-man stage shows, particularly Pigspurt, Furtive Nudist and Knocked Sideways.

Unfortunately, the last time I saw him was in the less satisfying Meaning of Life at the Drill Hall 3 or 4 years ago, but I still have great memories of those earlier shows, and the strange but entertaining evening a friend and I spent in his company in 1992.

Guardian obituary with link to Billington tribute etc