“Pink Floyd” was (is) a fictitious character - sort of. Syd Barrett named the group after his 2 favorite blues artists, Pink Anderson and Floyd Council.
Jethro Tull was a real person: An English agronomist, agriculturist, writer, and inventor of considerable repute in English history. (Many people used to think Ian Anderson was “Jethro Tull”.)
Uriah Heep was a character in a Dickens novel.
Tull and Heep are still touring!
/sarc