The avian/humanoid hybrid or giant bird is the indigenous lifeform to Brontitall. These lifeforms once lived as people in a civilization that fell into economic depression due to the Dolmansaxlil Galactic Shoe Corporation's efforts. They now inhabit a fifteen mile tall statue of Arthur Dent Throwing a Styrofoam Coffee Cup.
The Dolmansaxlil Corporation made use of the fact that many people were depressed and looked at their shoes a lot. The people looked down at their shoes when they were depressed and decided they needed a more expensive pair. The Dolmansaxlil Corporation made use of this by making all the shoe shops sell shoes that were too wide or small and that fitted nobody, therefore constantly making people seek better shoes, which they could never find. Soon, shoe shops took over Brontitall and in the resulting economic collapse, the people evolved into birds.
Before the Shoe Event Horizon destroyed their civilization , the people saw a wormhole appear in the sky, showing Arthur Dent throwing a styrofoam coffee cup. This is because he was annoyed that the Nutrimatic Appliance on board the Heart of Gold did not make traditional tea like Arthur Dent experienced on Earth. The people took this as a sign that they should remove robots from their lives. They shipped all their robots to work as slaves making toupees for planets which had run out of trees due to deforestation. A statue was made, with the styrofoam coffee cup hanging in mid air, held aloft by the Power of Art. Since it is artistically correct for the cup to be where it is, there it remains.
The statue's left ear is now where the birds live and the statue's face is covered in droppings. They are ruled by the wise old bird and never go to the ground, for it is now ruled by the Dolmansaxlil Corporation. It is guarded by foot robots, armed robots which prevent outsiders or birds from setting foot on Brontitall's ground level. All the robots have a limp since their shoes do not fit and are all too wide or too small.