Hurrah! You are correct, Trevor. Well done. I shall now reveal all.

The quotation appeared in a Sunday strip. You may recall that Bill the Cat had, during his sordid career, formed a heavy metal rock group in which he was the lead singer and also played the tongue (his tongue, of course). The group was initially called "Deathtongue", with an umlaut over the "o" in "tongue". Opus the Penguin was also part of the group, as were a couple of other characters from the strip. One of their big hits was called "U Stink But I Love U" (with a heart symbol for the word "Love"...naturally...that was very much the style in music at the time). They later renamed themselves "Billy and the Boingers" and pursued fame, fortune, sex, drugs, the usual stuff...

I think that sleazy lawyer Steve Dallas was involved too, but I can't recall in what capacity.

At any rate, this Sunday strip was a parody of the Barry Manilow hit playing above Bill's and the band's gyrations...and I paraphrase it (cos I can't exactly recall all the lyrics)...it went kinda like this:

Bill howls the songs that knot my underwear...
Bill howls the songs that make me tear out my hair...
Bill hows the songs that make the young girls cry...
He howls the songs, Bill howls the songs...
Bill is gross buckets...and he howls the SOOOONNNNNNGGGGGS!