What Does Krillion Mean? The Made-Up Number Behind the Pun

A krillion is not a real number. It is a blend of "krill" and "million", a joke word for an amount of krill too large to count. It has no fixed value, the same way a zillion or a gazillion has none. Its best known use is in the 2011 animated film Happy Feet Two, where a krill named Will tells his friend Bill, "There's only one of me in all the world. I am one in a krillion."

So "one in a krillion" means what "one in a million" means, with a krill pun on top: something, or someone, rare enough to stand out from a vast and identical crowd. That is also the whole idea behind Krillion, our word game, where the rarest correct answer you can find is the one that scores. But the word sits in a much older and stranger family of made-up numbers, and the real numbers behind krill are big enough to make the joke almost literal.

No. No dictionary or mathematical naming system gives "krillion" a value. The real large numbers in English (million, billion, trillion, quadrillion and onward) are built from Latin prefixes for two, three, four and so on. There is no Latin prefix "kr-", so a krillion cannot slot into that ladder anywhere.

If you want an honest answer to "how much is a krillion?", it is the answer you would give for a zillion: a lot, more than you could ever count, and probably said with a grin. Linguists have a name for exactly this kind of word.

The linguistic anthropologist Stephen Chrisomalis studied these words in a 2016 paper in the journal American Speech, "Umpteen Reflections on Indefinite Hyperbolic Numerals". His label, indefinite hyperbolic numerals, describes words that look like numbers and behave like numbers in a sentence ("a zillion emails", "umpteen times") but point to no particular number. They are vague and exaggerated at the same time, which is precisely their job.

Searching digitised newspapers, Chrisomalis pushed many of these words back further than dictionaries had them:

• Squillion, the oldest of the rhyming family, turns up in 1878.
• Umpteen appears as "umteen pence" in a New Zealand newspaper, the Christchurch Press, in September 1878, forty years before the Oxford English Dictionary's earliest citation.
• Zillion had long been credited to the writer Damon Runyon in 1944. Chrisomalis found it in the Oakland Tribune in December 1916, and noted that most early uses were in African American newspapers and magazines.
• Jillion emerges in the mid to late 1920s, with the earliest examples from Texas.
• Bazillion follows in 1939, kazillion in 1969 and gazillion in 1974.

His finding was that most of these words appeared between about 1880 and 1930, often in American writing, and that the most successful ones rhyme with million. Krillion is a late, aquatic member of the same club: it rhymes with million, it acts like a number, and it means nothing precise.

"Million" came into English from French in the late Middle Ages, from the Italian millione, literally a big thousand. The later words were coined by analogy. A French manuscript by Jehan Adam in 1475 used "bymillion" and "trimillion", and the mathematician Nicolas Chuquet wrote out a whole series in 1484, swapping in Latin prefixes: bi-, tri-, quadri- and so on, each step meaning another power of a million.

That original system is called the long scale, where a billion is a million million (a 1 with 12 zeros) and a trillion is a million million million (18 zeros). English mostly uses the short scale, where each step multiplies by a thousand instead: a billion is a thousand million (9 zeros) and a trillion is 12 zeros. The United States took up the short scale early. The UK used the long scale officially until 1974, which is why older British books can disagree with American ones by a factor of a thousand. Many European languages still use the long scale today, with "milliard" for the thousand million in between. The full story is laid out well in Wikipedia's article on names of large numbers.

This is the key difference between a trillion and a krillion. A trillion is a rule: tri- means three, so it is the third power in the system. A krillion borrows the sound of the rule and none of the arithmetic.

The phrase is a twist on "one in a million", an old English compliment for a person who is rare and precious. Happy Feet Two, released in November 2011, gave the pun its big moment. Will the krill, voiced by Brad Pitt, swims in a swarm where every krill looks the same. Bill, voiced by Matt Damon, points this out. Will refuses to accept it and says the line, then leaves the swarm to see what is beyond it. Near the end of the film, when Will comes home, Bill gives the line back to him: "About one in a krillion, Will."

The clip lived a second life years later. It was posted to YouTube in 2012 and became a meme in the spring of 2023, when "I am one in a krillion" spread across TikTok and Twitter as a tongue in cheek way to announce your own uniqueness. The joke works because it is a little absurd: a krill claiming to be special, from inside one of the largest crowds of animals on the planet.

Here the pun nearly stops being a pun. The most widely cited estimate of Antarctic krill comes from a 2009 study by Angus Atkinson and colleagues in Deep Sea Research I, which pooled decades of net samples. It put the summer population at around 800 trillion animals, weighing roughly 379 million tonnes. That makes a single species of crustacean, about 6 centimetres long as an adult, one of the most abundant wild animals on the planet by weight.

Inside a swarm, the crowding is extreme. Densities of 10,000 to 30,000 krill in a single cubic metre of water are often quoted, though instrument surveys in the open ocean usually measure far fewer, from hundreds to a few thousand. Either way, a swarm can stretch for kilometres and be spotted from an aeroplane as a pinkish patch of water.

And the crowd used to be bigger. A 2021 study in Nature led by Matthew Savoca estimated that, before industrial whaling, baleen whales in the Southern Ocean ate about 430 million tonnes of Antarctic krill a year, more than the entire stock today.

So if a krillion means "as many krill as there are", the real figure is in the hundreds of trillions. Will's boast was close to the truth: being one in about 800 trillion is not far off one in a krillion.

In the Krillion game, "One in a Krillion" is not a slogan but a score. Each prompt asks for something in a category, say a cheese, a river or a film, and every answer the game accepts is graded by how rare it is. There are six tiers, and each rung doubles the one below until the ceiling: Plankton 4 points, Too Clever 8, Schooler 16, Rare 32, Deep Cut 64 and One in a Krillion 100.

The surprising part is how many answers deserve the top tiers. In our analysis of Krillion's prompt banks, covering 2,524 live prompts that accept 137 distinct answers on average, 14.7% of all accepted answers are One in a Krillion and another 26.2% are Deep Cuts. Only 5.3% are Plankton. In other words, rare answers are not rare at all in the list of what is true. They are rare in what people think of first. Titanic is a Plankton answer on 22 different prompts, Paris on 17: the crowd reaches for the same few things every time.

That is the swarm Will was trying to leave. Your score becomes your depth, too: every point sinks your krill 10 metres, so a perfect seven prompt dive of 700 points reaches 7,000 metres. If you want strategy rather than etymology, our guide on how to get better at Krillion covers it.

Every indefinite hyperbolic numeral is a small act of exaggeration. A krillion is the only one that comes with a test attached. Krillion Unlimited is free, runs in your browser with no sign up, and has no daily cap, so you can try a prompt, see where your answer landed on the ladder, and try again. Somewhere in a bank of a hundred or more valid answers is the one nobody else thought of. Finding it is the closest a person gets to being one in a krillion.

Chrisomalis, S., Umpteen Reflections on Indefinite Hyperbolic Numerals (American Speech, 2016).

Atkinson, A. et al., A re-appraisal of the total biomass and annual production of Antarctic krill (Deep-Sea Research Part I, 2009).

Savoca, M. S. et al., Baleen whale prey consumption based on high-resolution foraging measurements (Nature, 2021).

Wikipedia, Names of large numbers.

Happy Feet Two (Warner Bros. Pictures, 2011).