i've never had a korean melon

when i go to the grocery store, i tend to pick random fruits and vegetables i've never had just to try them. i saw one last week that i'd never tried before. the closest sign to it was 'korean melon'. i decided to give it a shot. when i brought it up to the cashier, she asked what it was and i replied 'korean melon'. i then took it home and started the usual routine of googling/youtubing it to see what people do with it. all pictures/videos that came up showed a round-ish yellow fruit; whereas this was a long green smooth oval. 'deformed and unripe?' i thought. i let it sit for a week till it finally started to get some black spots. no, i guess this won't ripen any further. might as well make the best of it. i began to slice it open and my knife got stuck quarter of the way through. tried from the other side, then finally pulled it open to find that it's... a giant avocado! i still have never had a korean melon.