Name: rocket sparrow, jack, jet beetle, ghost pepper birb.
1: towhee
a: feathers
b: general body plan
2: bombardier beetle
a: hydrogen peroxide glands
b: reaction chamber
c: exoskeleton
d: 6 limbs
e: an extra pair of wings, but mostly used as leaves or steering appendages
3: auxenochlorella pyrenoidosa
a: the whole thing as an endosymbiont in all the skin/exoskeleton, feather, sclera, and egg cells cause this thing’s goin’ oxygen free places at some point.
4: fruit bat
a: hindlegs and forelegs can act as wings due to a skin connecting them to the main body/exoskeleton. these wing membranes get scales and bloodflow control instead of an exoskeleton due to high mobility requirement
description:
the rocket sparrow is a sparrow with a chitinous, nerve ending free combustion chamber (with more than trace amounts of silver as a catalyst) that has a nozzle coming out of it and going past the cloaca to prevent the bird getting burned by its own flames. said combustion chamber is fed by a bladder lined with epidermal tissue that constantly has highly concentrated hydrogen peroxide put in it by a few dozen hydrogen peroxide glands. this bladder uses a few one way valves to ensure the explosion doesn’t go backwards.
due to being able to go up where the air is thinner than a bird should be able to breathe, rocket sparrows have the ability to close off their nostrils so they can’t have any gas enter or escape them, an exoskeleton under their feathers that only grows in after reaching maturity to keep in pressure and prevent them from exploding under too little pressure because of holding their breath, bloodflow in the hairs of their feathers that doesn’t get cut off in the final set of feathers (it’s the final set because it’s the one after the last they shed) to allow their currently eukaryotic chloroplasts to have as much surface area to photosynthesize as possible, speaking of which, they have green eyes from their endosymbiotic chlorella having enough light to survive in the scleral and iris cells and not impeding sight while there
the first step of the female ghost pepper birbs choosing a mate is finding a group of male jacks, the second step is seeing how high all of them can fly, with all but the top three being disqualified from further stages of the competition. the third stage is having them all fight to see who is the strongest, with the winner being the one the female jack chooses. this means that over time the ghost pepper birbs will adapt to fly higher and higher until or past them exiting the mesosphere before they evolve proper rocket fuel.
all jacks have 4 pairs of wings, two of which are used for walking, one of which is primarily composed of chitin and is mainly used for photosynthesis, and the last of which is only used for flying, but does aid in photosynthesis, and can fold down against the body to protect the thinner insect wings underneath them
while jet beetles are resistant to low pressures, they cannot yet withstand a vacuum as their eyes are not covered by something hard and clear, and thus would depressurize in a vacuum, especially if the jack is holding its breath