greek-grak-grok-groke-gruke
One time I lived with this 5-year old and I used to make up stories for him when we took the bus to his school in the mornings. One day I made up some story about a monster and he was very insistant about what the monster was called, so I told him that it was called a Greek-grak-grok-groke-gruke. Then he wanted to know what it looked like, so I folded up the tip of my tongue into the shape of a "w" (a talent of mine) and said, "It looks like that."
"Oh," he said. For some reason that seemed to make everything perfectly clear. I told him the story and then forgot about it for a long time, and then, about a month later he brought me a picture he drew, and I asked him what it was, and he told me it was a Greek-grak-grok-groke-gruke. The funny thing is, is that it was a little stick figure, but it's head looked a lot like my tongue when I'm folding it up into a "w". His mom was pretty impressed. She framed it.