Conversation so far:
What was the first riff of the song Hound Dog?
The Latin riff form that was used in Elvis Presley's Hound Dog was known as Habanera rhythm, which is a Spanish and African-American musical beat form.
Who wrote the first riff of the song Hound Dog?
Just as Bill Haley had borrowed the Latin riff from Dave Bartholomew, Elvis Presley borrowed it from Bell and the Bellboys.
What song, other than Hound Dog, had the Latin riff?
The Latin riff was also used in Rufus Thomas' Bear Cat, the first and most popular answer song to Hound Dog.

Question: Who was that by
Self-contained rewrite: Who was the song Bear Cat by?