When doing something that would fall under the terms of general douchebaggery, or other rambunctiousness, a person might use I am dick. Very similar to how someone would call themselves a dick jokingly, because that's exactly what it is. Commonly used online.

Origins are unclear, but are often thought to stem from a

anti-bullying Facebook post typo that was quickly spread across popular culture.

Note that I am dick and its variants are NOT used as insults.

Also used:
You/He am dick - When joking about another person.
I/You wam dick - When you did something I am dickish in the past.