Conversation so far:
What was giant killer and why was Rey Mysterio called that?
Rey Mysterio became a giant killer by defeating large opponents such as Kevin Nash, Bam Bam Bigelow, and Scott Norton.
when was Rey Mysterio's unmasking?
In 1999, Rey Mysterio lost a Hair vs. Mask match, forcing Mysterio to remove his mask.
what happened after Rey Mysterio's unmasking?
Rey Mysterio publicly expressed his disappointment over being unmasked.
did Rey Mysterio win any titles?
In July at Bash at the Beach, Rey Mysterio defeated Psicosis to earn another opportunity at the Cruiserweight title. The next night, he defeated Malenko to win his first Cruiserweight Championship.
did Rey Mysterio set any records?
On the June 17 episode of SmackDown!, rey Mysterio defeated Chavo Classic for a record-setting third Cruiserweight Championship reign.

Question: did he do anything else that gained him fame?
Self-contained rewrite: did Rey Mysterio do anything else that gained him fame, besides his Cruiserweight Championship?