42nd President: Bill Clinton, 1993
Rain = 42 (Clinton was the 42nd president)
Klingon = Clinton
NOTE: In order to know what a Klingon is you need to watch Star Trek.
Puppy home = 993 = 1993 became president
Bill (receipt) = Bill
The rain (42) poured down as the Klingon (Clinton) went to the puppy home (993 = 1993) to collect his new dog.
Connect Clinton to Bill:
The Klingon (Clinton) was shocked at the bill (Bill) he received for the new puppy.
NOTE: The way Mammoth Memory remembers Bill is to think a bill.