Doug "Dougie" McElroy is the "secret" fourth brother of the McElroy siblings, as mentioned in the intro of the third episode of the MBMBAM Seeso show.
His creation is the result of a quip from Griffin ("[Outvoted by] the secret fourth McElroy brother, Dougie") in response to Travis stating at the beginning of the episode, "I looked at this question and I said, "NO," but I was outvoted three to one." This vote count was later clarified later to include the two other brothers and the director.
In Episode 60: Discretion for Miles, the brothers mention a fourth brother named "Terry"; it's unclear whether this is another name for Dougie or another person entirely.
- Clint is not cruel enough to name a child "Dougie". Because of this, it is likely that it is a nickname.