birthdayzilla Share definition Flag A person who places way too much emphasis on their birthday to the annoyance of anyone even remotely acquainted with them. "OMG guys my birthday is in 196 and a half days!" Oh my gosh Thomas you are such a birthdayzilla. birthdayzilla by silkyswag October 8, 2016 0 0 Get merch Get the birthdayzilla mug. Buy Now — $32.95 See more merch