TierZoo is a viral YouTube sensation that blends zoology with gaming culture by treating the natural world as a complex MMORPG called 'Outside.' Since its debut in 2017, the channel's unique aesthetic—featuring tier lists, RPG stat bars, and gaming terminology like 'nerfs,' 'buffs,' and 'specs'—has become a widespread meme format. Users utilize this template to mock the 'viability' of different species or to explain biological traits through the lens of competitive gaming. It is the go-to format for anyone wanting to humorously analyze why a honey badger is 'overpowered' or why certain species are struggling to survive in the current server meta.