For more than 40 years, young tabletop game enthusiasts have engaged in spirited competition involving four plastic hippos and their insatiable appetite for marbles. In Hungry Hungry Hippos, players hover over a proving ground full of 20 plastic balls. Using a lever, they open and close the mouths of the hippos until the marbles are gone. The hippo with the most marbles at the end is the winner. The Hasbro game is a lesson in hand-eye coordination, tolerance for a lot of racket, and an exercise in the benefits of gluttony. Check out a few things you might not know about this enduring favorite.

1. Hungry Hungry Hippos was brought to the U.S. by a World War II veteran.

As a boy, Fred Kroll knew he wanted to be in the toy business. His father manufactured cardboard games that Kroll would peddle in and around New York City. After a stint in the U.S. Army during World War II, Kroll went to work as a salesman for the Pressman Toy Corporation. He later discovered Hungry Hungry Hippos in Japan. Kroll licensed the international rights to the game from the Agatsuma company in Tokyo. It became a huge seller. After selling those rights to Hasbro, Kroll—who died in 2003—maintained that the game’s royalties were enough to live on.

2. The hippos in Hungry Hungry Hippos had names.

When Hungry Hungry Hippos debuted under the Milton Bradley label in 1978, each of the four marble-gobbling hippos had names. Lizzie Hippo was the purple one; the orange one was Henry Hippo; Home Hippo was green; and Harry Hippo was yellow. Later versions changed the colors, the names, or both.

3. There’s a kid-sized version of Hungry Hungry Hippos.

In 2018, child vehicle brand Kid Trax partnered with Hasbro to launch a series of foot-powered ride-ons named the Hungry Hungry Hippos 3-in-1 Activity Rider. The cars are shaped like the hippos, with the mouths moving up and down just like the game to allow kids to “eat” the included balls. While this sounds like a fun time for anyone, the vehicles are only suitable for kids ages 3 and under.

4. There’s also a human version of Hungry Hungry Hippos.

Some communities have taken to ice rinks to play a modified version of Hungry Hungry Hippos by propelling humans around the surface. Using baskets, they try to “eat” as many balls as possible. The Grand Rapids Snow Days in Grand Rapids, Michigan hosted an event in 2017. A version is also promoted at the DC Wharf Ice Rink in Washington, D.C.

5. There’s a Guinness World Record for completing Hungry Hungry Hippos.

In 2018, Manchester United soccer player Axel Tuanzebe set the Guinness World Record for the fastest game of Hungry Hungry Hippos ever completed. Tuanzebe gobbled up all 20 marbles in an official time of 17.37 seconds.

6. There’s a Hungry Hungry Hippos world championship.

For players with exceptional hippo prowess, the Gen Con tabletop gaming convention in Indiana hosts a showdown for bragging rights. The Hungry Hungry Hippos World Championship has been held annually since 2015 and invites players aged 6 and over to compete. In 2016, more than 100 players vied for the title of hungriest hippo. The winner received a hippo mounted on a plaque.

7. Hungry Hungry Hippos might be a movie. Someday.

In 2012, Hasbro announced that the Emmett/Furla production company had entered into an agreement to produce feature films versions of several notable Hasbro properties, including Monopoly, a British toy line called Action Man, and Hungry Hungry Hippos. Presumably a giant-animal-on-a-rampage scenario, the film has yet to enter production.