https://www.pinterest.com/pin/320177854754704362/
http://www.applearts.com/content/the-raven-animal-art-oil-painting
https://www.dndbeyond.com/monsters/swarm-of-ravens
https://www.belloflostsouls.net/2017/02/dd-unearthed-arcana-warlocks-n-wizards.html
https://www.pinterest.com/pin/380343131005409860/
https://www.pinterest.es/pin/432556739199366040/