Parlor Roller, they are basically pigeons with epilepsia that manifests once they mature. So they are unable to fly and are ‘raced’ by letting them 'roll’ on the ground, wing flapping, twitching…if they are stressed too often they might die from it. There are videos on youtube with them being raced
We’ve discussed Parlor Rollers here before
And believe it or not, that isn’t epilepsy.
That is a skeletal-muscular deformity.
This is just what happens when Parlor Rollers try to fly.
You can see it try to return to the shadow of its handler a few times.
They are also bred high strung and skittish so that once startled into a roll, the roll itself frightens them into continuing longer.
It look this poor bastard over three and a half minutes just to right itself.
In the video, you can hear the competitors insisting this bird be bred for its exceptionally long roll while in the same breath talking about how often hawks snag them.