First, a hint: The answer does not rely on any word play or the phrasing of the question. It’s just a really hard question that everybody knows the answer, but never thinks about. And so it’s hard to come up with. Here it is:
Name a mammal where if every one of them on the planet died today, there would still be more next year.
Put your answers in spoiler boxes, please.
Platypuses and spiny anteaters?
Mules?
Your answer is better than mine.
a mule since it’s a crossbreed. Also works for a liger.
I probably had more fun with the riddle too. 
Humans - There are six on the International Space Station at the moment, and they’d probably decide to land eventually
That is correct. Isamu, you also got it.
Sorry. Johnny LA but if you think about it, your answer wouldn’t work.
pericynthion, interesting, but I’m going to have to say no.
Misunderstood – I thought you meant there’d be an increase next year.
Yeah, I doubt they’d be able to land without some help from humans back on Earth.
[spoiler]I suppose that this sort of relies on wordplay but, if you count people in airplanes as not being on the planet, then I’ll say humans.
Some would manage to land without ground assistance, and I suppose some number of those would survive the complete collapse of civilization at least a year.
The phrase “more of them” makes me suspect I’m wrong, since “more” seems to imply new individuals, but it’s all I’ve got.[/spoiler]
ETA: Actually, if the above answer is correct then some alternate answers would be cats or dogs or possibly others, since there are likely to be some pets in the air at any given time.
Can someone explain this to me, please?
Thanks.
In the same vein as my previous response, if not being on the ground is considered to be “not on the planet” then “bats” would also be a valid answer.
A mule is a cross between a (female) horse and a (male) donkey. As such, if all of the mules died, so long as horses and donkeys kept inter-breeding, we would have new mules next year.
I’m quite certain that cats and dogs, and probably cows pigs and horses, among others, would also be correct- if every one of them somehow died today, there are enough eggs and sperm to make plenty more, and people definitely would. unfertilized Eggs and sperm should definitely not count as having to be included in the death of every one
A mule is the offspring of a male donkey and a female horse. If you killed off all mules today, there would still be male donkeys and female horses, therefore tomorrow (or sometime in the near future) there would be mules.
How about dogs and cats. If they all died we would still have puppies and kittens, which would later become dogs and cats.
Not looking at the rest of the thread:
The platypus lays eggs, so they can hatch after the platypucalypse.
And where are you going to put those eggs and sperm once you fertilize them? in vitro fertilization is an amazing thing, but at some point you still gotta stick the fertilized cell(s) back into the animal.
Thank you. I’m not sure I ever knew that – silly city girl that I am…