A serialized webcomic called Bulltardia is hiding twelve keys that form a seed phrase for a Bitcoin (BTC) wallet containing 0.1 BTC. The first two episodes are included in volume three of the Bitcoin culture fanzine Citadel 21.
There have been a number of opportunities for those who like cryptic puzzles and free Bitcoin, from early treasure hunts through the streets of Barcelona to clues hidden in graffiti art and even an album full of music.