Quagnoth is not a person. Quagnoth is a creature (beast) card that was printed in the future sight expansion.
If your question relates to the rules mechanic of:
"When a spell or ability an opponent controls causes you to discard Quagnoth, return it to your hand."
Than it is referring to itself, if you discard the (creature) card titled Quagnoth, than it returns itself to your hand. It's essentially a creature that you cannot be forced to discard.