When I initially got an ATTINY85 from Digispark, I wanted to use it as a rubber ducky. I intended to have it run EvilOSX when plugged in, however, due to limitations on the ATTINY85, I was unable to flash the duckyscript generated by EvilOSX. I instead wrote a simple script to easily fetch and run python payloads using curl, deleting it afterwards.
Simply upload your python script to pastebin or your preferred service, and replace the link in the code. Flash it to your ATTINY85, and you're done!