It's part of Greenpeace propaganda to shame bitcoin’s users into renewing the code but turns out the users like it.

https://cointelegraph.com/news/greenpeace-war-on-bitcoin-unintentionally-spawns-badass-new-mascot

Ripple co-founder Chris Larsen paid Greenpeace to make a campaingn against Bitcoin. Main narratives against bitcoin and proof of work are energy use are high energy use and e-waste, both of which are based on false/old data.

An envirometal topics spezialiced artist Von Wong was contracted to make an art installation for the campain. He made a real masterpiece - the green skull.

Many bitcoiners thought that the art pice was really cool, and also noticed the endless memeing possibilities. It is some of the most badass bitcoin art ever done.

The artist jas DM:d in twitter. The misconceptions behind his art were corrected and he is already half way to bitcoiner. Hopefully he will do more bitcoin art in future.