Complex sentence: Fat Freddy's Cat first appeared in 1969 in underground newspapers as a character in "The Fabulous Furry Freak Brothers" strip, and later had his own small topper strip, in imitation of the early Krazy Kat strips below The Family Upstairs by George Herriman.
Split into simpler sentences: Fat Freddy's Cat first appeared in 1969 in underground newspapers as a character in "The Fabulous Furry Freak Brothers" strip. He soon gained his own small topper strip, in imitation of the early Krazy Kat strips below The Family Upstairs by George Herriman.