More like a pride of lions bringing down an elephant, or maybe wolves on a bison.

1v1 dragon slaying would still be more like a badger taking on a tiger.

Player characters (as opposed to non d&d dragon slaying stories) aren't usually as ill prepared as a cat is vs a human, and rarely "hunt" alone. PCs have better weapons than claws and teeth, and the ability to coordinate attacks reduces the advantage of size and power the dragon has more than the comparison between a cat and a standard, unarmed human.

I do, however, love the idea presented :)