The Gelatinous Giant is one of the Demons of Ignorance from the book and movie The Phantom Tollbooth. He blends in with the environment to capture his victims. He was about to eat Milo and his friends until Milo mentions about an idea (the one thing the giant can never swallow). When Milo showed the giant the bag of words from King Azaz, the giant melted to nothing.
"An idea? Ugh, if there's one thing I can't swallow, it's an idea!"
"NO! No no no! Don't open it! Leave well enough alone! Don't take chances... keep things as they are... changes are so frightening... no... new... ideas..."