[diverjohn (OP)]

The peregrine falcon is ranked as the fastest animal in the world, reaching 242 MPH in a dive. However a comedian remarked that an elephant, if pushed out of a high-flying cargo plane, could beat that bird and thus become the fastest animal on the planet. After a laugh, I wondered if that were true. Of course air resistance would be the limiting factor in a free-fall calculation and so I wondered about the poor aerodynamics of the elephant's body and thought a sperm whale might achieve a higher speed if it kept its orientation as "head down".
any thoughts on this? Is there a list of animals ranked by body density and streamline shape?
And please, no rude comments from PETA (physicists for the Ethical Treatment of Animals).

[RD]

The peregrine falcon is ranked as the fastest animal in the world, reaching 242 MPH in a dive.
However a comedian remarked that an elephant, if pushed out of a high-flying cargo plane, could beat that bird ...

Unfair comparison: the peregrine falcon record is powered flight downwards, not free fall.

Horizontally anyone can legally overtake a peregrine falcon on the motorway, (if they're driving a vehicle  ).
https://en.wikipedia.org/wiki/List_of_birds_by_flight_speed

[Kryptid]

One would need to know the drag coefficient of an elephant in order to get the right answer, but I doubt anyone has measured it. I do know that terminal velocity increases with increasing size (assuming a constant drag coefficient, that is). This is because the mass (and therefore the force exerted by gravity on it) increases faster than an object's surface area and cross-sectional area does (which is what drag scales to). A human being's terminal velocity is about 190 kilometers per hour, so a human being scaled up until it was the mass of an elephant would definitely fall faster than that.

[Bored chemist]

I think we can assume the elephant is spherical... and then circular.
But it misses the point. if you had an elephant in a cargo plane it could easily exceed 242 MPH anyway.
The fastest animal that we know about is the human.

[alancalverd]

But the word on the card is "fall", so I'd vote for a blue whale, nose down, or possibly a large shark. All aquatic mammals and pelagic fish have minimal drag coefficients.  Not having lungs, it is possible that sharks are denser than whales.

[Halc]

I'd vote for a blue whale, nose down

Who's thinking:

Hey! What’s this thing suddenly coming towards me very fast? Very very fast. So big and flat and round, it needs a big wide sounding name like … ow … ound … round … ground! That’s it! That’s a good name – ground!

I wonder if it will be friends with me?

[alancalverd]

Known in aviation circles as cumulus solidus.

[Petrochemicals]

Jellyfish, being of such constituency they would form to the drag and the surface covering you could assume would be quite slippery,

[evan_au]

Which animal will fall with the greatest velocity?

It depends on what height you fall from - and especially, whether it is falling through air or a vacuum.

I vote for the Apollo 13 astronauts,who did an accelerated loop around the Moon (because they were running out of air and battery power), and then did a free fall back into Earth's gravity well from almost the orbit of the Moon.
- Of course, that includes all the microbes that they were carrying with them

Although, any microbes hitching a ride on the Juno mission will fall into an even deeper gravity well (as will any passengers on the Parker Solar Probe)...

[Malamute Lover]

Known in aviation circles as cumulus solidus.

You mean a mid-air collision with a planet?

[alancalverd]

Cumulus mediocris, fluffy low-level clouds, sometimes contain bits of cumulus solidus, or mountains. The official report is usually headed "Controlled Flight Into Terrain" if the aircraft is within the normal flight envelope, or "Loss Of Control" if the impact is substantially vertical and out of envelope, like a spin or a cold balloon. Either way, unintended contact with solids can spoil your day.