This is a simple reversible mock-rib style beanie that can be made fairly quickly.
I have made 3 in an evening while watching Netflix. :)

S = 18 - 19”, M = 20 - 21”, L = 22 - 24”

Any heavy worsted/aran weight yarn can be used.
You will need (approximately):
• Main Colour – 200 to 250y
• C1 – 25y
• C2 - 20y
• C3 - 15y

Note: This is not a messy bun hat, but I suppose you could easily alter it to be one if you really wanted to.