Tigris and Euphrates? But are people intelligent enough (on average) for that to be an issue? Maybe not. The sound of Tigris is pretty cool. I'd say male.
Egret sounds horrid to me. Like the sound one makes before one vomits. Is that a bit melodramatic? :) Plus it's so close to 'regret'. It'd be funny on a dog for some reason, but not okay on a person.