For this challenge I immediately noticed the emojis and thought it must be emojicode (Don't ask me why I knew it existed). I decided to try and get code execution using emojicode's system interface. This was a little hard to figure out, but after viewing some file reading examples I was able to figure out how to call this function. It seems to be that calling a type function of a class was in the general form <typefunctionemoji>rabbit<classemoji> and then then the arguments (in this case a string) followed by a red exclamation mark to end the arguments.
Once I had code execution I found that the server had curl, and used that to get the flag from the `emojiwat-flag` host: