So yeah, write down what the weirdest trade you made on the GTS.
Mine occurred just a while ago, when I was searching for Cobalion in the GTS, I saw one that asked for a Deerling (F) level 20 and up in return. I didn't have any at that time so I searched in The route where you can find Deerlings. I saw Karrablast, Vannilites and Foongus. I also saw 3 male Deerlings, I thought I was out of luck, but then I found one, a female Deerling. I used Hypnosis on it and I Caught it on my first try. Now, I got a Level 48 Cobalion, together with my Level 42 Cobalion.
In short, I got a Cobalion in return for a Female Deerling.
What is your story?