The Rat King boss fight is one of the more memorable sequences in The Last of Us Part 2, but it didn’t have its name until late in development.
One of the more intense encounters in The Last of Us Part II is the boss battle against the Rat King. While playing as Abby, players encounter the Rat King in the basement of a Seattle hospital – one of the series’ few unique infected enemies, inspired by the bosses of other PlayStation exclusives. The sight of the Rat King in TLOU2 is as horrifying and disturbing as the boss is dangerous, and has become one of the more memorable moments of a game full of key interactions. Oddly, this central enemy in the game was not even originally afforded a name and was only given the Rat King designation as an afterthought.
On the second day of controlling Abby through Seattle, players delve into the basement of a hospital in order to find medical supplies. Deep in the recesses of the infected building, in areas not explored since the outbreak began, Abby encounters The Last Of Us 2‘s creepy Rat King, an abominable amalgamation of infected. It’s implied that the Rat King has been growing in the depths of the hospital since the earliest days of the outbreak, with the fungal nature of the cordyceps virus eventually leading to confined victims growing together into the monstrous being Abby finds.