Yes, this is a t-shirt, and yes, you should buy it immediately. From the designer.
“It’s the Great Old Ones’ favorite beverage, guaranteed to be maddeningly refreshing! Cthulhu himself enjoys kicking back after a hard day’s work in R’lyeh and pouring himself a tall cold glass of Cthul-Aid, and so should you!”
One of these days, I’m actually going to make it through a Lovecraft book. But right now I’m reading A Song of Ice and Fire over again, so perhaps next year.