What do you call multiple quintuplets that look the same?
Naruto's mom.
Naruto's Mom
Explanation
Explain Bear
Okay, so, imagine you have a bunch of babies, like five of 'em, and they all look exactly the same. Now, think about Naruto, that ninja dude. The joke is playing on the word "multiple" and "quintuplets" which sounds like "Naruto's mom". It's a play on words, you wouldn't get it.