The one who can open their mouth the widest to take in the largest malescrotum (or teabag). It can also apply to who can suck on a teabag the longest, depending on the context.
Lance and Gary had a contest to see who was the real bagmaster at the party.
Someone or something that bites your ankles.
To a postman, an ankle biter is often known as a dog.
To an adult, an ankle biter may be a toddler.
To hikers, an ankle biter is sometimes a tick.
And so on.