Only the other ducks.
When we are walking in the back yard he will run after us with his head down ready to nip our Achilles tendons in half. But somehow no matter how slow we go, he never quite catches us. And if we should turn around and look at him, he will stand upright and casually wander away.
He is also VERY tough and will NOT run away from us. Like the rest of the ducks if we slowly walk toward him, he will stay 1-1/2 arm's lengths away. But if we speed up, he will stop and wait for it: "I'm not scared." So i will scratch his chest and pet his back. He tries to meander off but I give him a pet from that direction saying nice things to him all the while... He HATES it.
Sounds like a stalker drake.