I'm A Ducky - Someone who thinks they're the best but is just a loud, clum

Someone who thinks they're the best but is just a loud, clumsy, overconfident mess.

I'm a ducky because I tripped over my own feet in front of the whole class.

I'm a ducky because I claimed I could do 10 push-ups and only did two.

I'm a ducky because I tried to be funny and nobody laughed, so I kept talking more.