Yelling Bird is a bird with a bad temper and a loud voice, which he uses to spew profanities. He originated in Jeph Jacques' side-comic indietits before eventually becoming (almost) part of Questionable Content. He lives with a girl whom he only refers to as Sweet-Tits. He is also annoyed greatly by a bandicoot named Randy and a dog named Shelby. Yelling Bird and his companions do not appear (or hardly ever) with the rest of the cast, and it's possible that they don't even exist in the same universe. They usually appear as filler comics when Jeph is too busy or ill to do a proper strip.
The species of Yelling Bird is the Dickcissel, so named for the sound of its song. The template used for Yelling Bird comics is a photo from the Birds of Oklahoma site.
He seems to have some repressed memories, possibly due to a traumatic (and mysterious) event on June 14, 1987. When the date is mentioned, he violently denies that the day ever happened.
On the strip 3016 newspost, Jeph declared that "I am tired of Yelling Bird comics so there will be NO MORE OF THEM, goodbye you shitty bird", meaning that we will likely never see him again.