Flatulence Phoenix (edit)

Twisted by the dark magic that once flowed across the world, the flatulence phoenix has little in common with its proud brethren. It would have died out if not for the sorcerers, who discovered that the foul gas the sorry bird produces for levitation has many unique properties.
Where its fiery cousin rises from glorious flame this phoenix disappears in a cloud of acidic vapour with a disappointing pop. The putrid gases it produces build until the bird’s frail body can take no more and the resulting cloud slowly collapses in upon itself to form a new-born chick.
A careless sorcerer who forgets to draw out these gases hears the dreaded pop of the rebirth cycle which renders his laboratory uninhabitable for weeks.