LOL, exactly. One local bank had a magazine with the bios of some bank officers. It was the Stump family with first names of Forest and Oak. I was thinking were the rest of the family named Maple and Willow?
Maybe Adder is an old name but suppose they did just use the name because they liked the word? How is that different than the ghetto names the OP thinks are so bad?
Interesting point. Maybe "Adder" was the last name of someone in the family tree, or a mispronunciation of "Addie" or "Adair" that got passed down.
Whatever the source, at least it's easy to spell and pronounce.