Cleon
Legend
They're not going after anything super-big or threatening there. But I guess it does go on to say they have a reputation for being vicious. Well, anyway, I probably just misunderstood what wiki was trying to say....
The point is that a cockerel or rabbit is a big creature compared to a weasel.
Weasels can and will kill prey ten times their own weight (e.g. a 5 oz weasel killing a 3 pound rabbit). If a lion could do that it'd be bringing down smallish elephants single handed.
Oh, and rabbits have claws and teeth too, you know. They can put up a fight if they have to.