In the taxonomic sense? That's a philosophical question.

[Paul is teasing, mostly, although there is a sense in which it's not untrue - but that's a topic slightly too heavy for a party like this one, as far as Paul is concerned.]

The ones I mean are a lifeform native to Arrakis. Did you see the drawing over there?

[As if it's possible to miss a six by eight foot drawing of a towering armored worm bristling with teeth in its circular maw. Paul gestures to it anyway.]

They tunnel through the sand, and hunt by vibration. Even a single person walking on the sand can draw one from kilometers away.