The Milton Mule and Henry Bull —
In 1936 a candidate named Boston Curtis ran for the post of Republican precinct committeeman in the town of Milton, Washington. And he won. Unfortunately, and unbeknownst to the people who voted for him, Boston Curtis was a mule. His name had been placed on the ballot by the Democratic mayor Ken Simmons who guessed, correctly, that no one actually knows anything about the candidates for the lower-ranking positions. They just vote along party lines. Simmons figured it would be funny to get the Republicans to vote in a mule (which is the symbol of the Democratic party).
Carrying on this tradition of involving animals in the electoral process, we now have Brenda Gould, from Newmarket, England,
who registered her cows as voters. She listed their names as Henry and Sophie Bull. Oh, and she also registered her dog, 'Jake Woofles.' And on the same subject,
check out this Aug 2002 entry about a basset hound who was registered to vote in New Zealand.