Pullumism (Also known as Poultrism) is the belief that God is a Chicken in a literal sense. As outlandish as it sounds, this is a real heresy that stems from a Hyper-Literal reading of Matthew 23:37 and Luke 13:34. It is a rare and obscure heresy with an extremely small amount of adherents.
To the best of my knowledge, Pullumism is a new heresy. The earliest case I could find was a thread in May of 2016 from Yahoo! Answers in which someone asked if God was a chicken, and two people responded yes. In September of that year, Tyler Vela of The Freed Thinker Podcast had a discussion with a Seventh Day Adventist who adheres to Pullumism. He made a post on Facebook about it, saying, "I was debating and SDA guy tonight on various issues and the topic of polemics in the Bible came up. I showed him how God's strong right arm was a loan phrase from Egyptian motifs for the Pharaohs and how it was used to show that YHWH is the true God and sovereign and pharaoh is not. He then said that God actually does have a right arm because the text says so. I asked him sarcastically if God is also a hen because the scriptures illustrate God as a mother hen protecting her chicks. I wasn't prepared for him to double down and say that yes God was a hen. I asked if he just meant that God was LIKE a hen in someway. Nope. He meant that God had feathers and a beak and all - God is a giant chicken. No joke. I couldn't even..."
There are no known major adherents to Pullumism