How do Poro's reproduce?

They eat too much. Then there magically are more of them.

Alexa, this, is so, relatable. Can we impregnate Poros?

Fission just like dust bunnies.

{quoted}

Is exploding the answer? Do they lay eggs? Philosophy?

Actually, its a mix of the three answers... They lay eggs that explode after talking about Philosophy

You see, when a mommy Poro and a daddy Poro love each other veeeeeeeeeeeery much, they hug and their fluffy fur expands until they multiply into 4 Poros.

What if poros are, like, yordle larvae?

Magic?

You could say they're explosive breeders.