WARNING: The following contains spoilers for Pixar's Onward, in theaters now.

There are many mythical creatures featured in Onward, ranging from the elvish main characters to the centaur police and pixie biker gang. But while Barley and Ian are on their quest, they end up encountering an enemy not from actual mythology but one of the most popular fantasy games of all time.

The Gelatinous Cube, one of the oldest creatures from the Dungeons & Dragons games, has a minor role in Onward as a threat that almost brings down the adventuring duo.

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THE GELATINOUS CUBE

The Gelatinous Cube is a minor monster from the famous table-top role-playing game, Dungeons & Dragons. It was one of the original monsters conceived of by game creator Gary Gygax and appeared in some of the earliest editions of the game. The ten-foot cube initially appears to be just a square of ooze, but it's quietly a very alive and very dangerous creature, as it has the ability to mindlessly absorb and digest any matter that it comes into contact with.

The creature can move and ooze around corners and down halls, shifting shape depending on the surroundings. It also has a habit of being underestimated by cocky adventurers and will kill and digest weak enough players if it's got the chance. The creature is one of the most recognizable beings in the game and has appeared in various videogames and other media, such as showing up in brief gags during episodes of The Simpsons and Adventure Time. But in Onward, the Gelatinous Cube is given the chance to fully show how threatening it can become.

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THE ONWARD APPEARANCE

The Gelatinous Cube appears during Barley and Ian's quest to find the Phoenix Gem. While many of the magical elements that they've encountered have been a bigger part of the mundane-magic world around them, a dungeon at the end of a long cave feels from a very different time and place. The brothers barely escape a pressure-sprung trap, but Barley is horrified when a gelatinous cube appears behind them. The giant green square of goo doesn't appear to be a threat at first, but Barley's warning that the cube can dissolve anything is immediately proven. The pair quickly rush away, trying to outrun the cube as it slowly moves down the hall after them. It quickly proves to be a genuine threat, almost absorbing Barley before the two barely get ahead of the creature.

It's an interesting and effective use of the Gelatinous Cube in the quest and a great example of how these kinds of fantasy elements that can make adventuring so difficult. It also implies that Onward at least exists in a world where the creatures and effects of Dungeons & Dragons were at least similar to the established game series. Even something that is as seemingly easy to defeat as the Cube can turn out to have much more effect than one would expect. Hopefully, if there are any future stories within the Onward universe, they contain some more creatures from the expansive universe of Dungeons & Dragons.

Written and directed by Dan Scanlon, Pixar's Onward stars Chris Pratt, Tom Holland, Julia Louis-Dreyfus and Octavia Spencer.

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