We added a six month old shih-tzu to our family of three dogs, had her for two weeks trying to find an appropriate name. Feeding time was always interesting. One evening, my husband put down her bowl of food and she scarfed it down in a hurry! He said to me, "She eats like a little Hoover." Yep, that was her name from then on.
When we acquired a second shih-tzu, her name was Kirby. Had to continue the line.
Adopted this current shih-tzu and broke that pattern (Electrolux just seemed too long). His name is Little Guy because when I walked up to him at the shelter, I said, "Well, hello there little guy." It stuck. I considered "Jack" because he has only one eye.
Neighbor's Old English Sheepdog is named "Hoss", for obvious reasons.