Conversation so far:
What were some of Cosmo Kramer's pseudonyms?
He used the name H.E. Pennypacker
Which episode did Cosmo Kramer use this name in?
in The Puerto Rican Day“
What happened in the Seinfeld episode The Puerto Rican Day?
Kramer poses as a prospective buyer interested in an elegant apartment in order to use its bathroom

Question: What other names does he use?
Self-contained rewrite: What other names does Cosmo Kramer use?