List of theorems named after non-human animals I think it would be entertaining if we could come up with a list of theorems named after non-human animals (so excluding names like "Gauss's lemma" and the like). So far, I have only encountered two, or if there's more I can't remember them:
$1.$ The Butterfly Lemma (aka the Zassenhaus Lemma in group theory)
$2.$ The Snake Lemma of homological algebra
Is anyone aware of any more theorems named after animals? And if so, why does it have the name it has?
(I'm also not sure as to whether or not I should tag this question as a soft question, as it seems that whether or not a theorem has such a name has an objective answer, but I am happy to edit if need be.)
 A: If you're willing to stretch slightly further to philosophy, Buridan's Ass paradox is a good one, especially if the ass is mathematically inclined.
In probability, there's the infinite monkey theorem, because apparently monkeys can't read or write but there can be infinitely many of them.
A: The Pigeonhole principle (sorry Russians, I know you name it after Dirichlet and don't talk about the pigeons) is pretty classic:
If there are $n$  pigeons distributed among $m$ holes, at least two pigeons must occupy the same hole when $n > m$.
Now, this is certainly open to some debate: the theorem is really named after the holes, and not the pigeons. But, if the Bridge of Asses counts...
A: The Bridge of Asses  (Latin : Pons Asinorum) in Euclid. Here, ass does refer to the animal, not reknowned for its intelligence. The meaning is that an ass  cannot cross the bridge (by understanding the theorem).  The nuance is the converse: If you can't understand the theorem you are an ass and can go no farther in geometry.
A: Here are some mathematical theorems or solved problems named after farm animals:

King chicken theorem and other theorems about pecking orders (with chicken comics!)
Archimedes' cattle problem
Goat problem

Then there are mathematical objects (or related algorithms) named after animals:

Caterpillar tree, its cousin centipede graph, and the more distantly related lobster graph
Crocodile dilemma
Hydra game (technically Hydra is mythical so this doesn't count but it's an interesting game.)
Ant colony optimization

A: Here are some which, like the other answers, are not all strictly theorems:


*

*The busy beaver function, a classic example of uncomputability

*Dragon fractals, which I've seen appear in the theory of wavelets

*The butterfly theorem in plane geometry. Note this is distinct from the butterly lemma which OP mentioned.

*The Baire category theorem in analysis (kidding).
