- Alias: Kingrat, Rat King, King Ratboy, Kingsrat, Red Rat Boy
The Kingrat is nearly identical to that of the Ratboy, except its skin is a dark, crimson red, and it wears a crown, suspenders, white shoes, and royal shorts. It also emits fire particles around itself and wields a red sword emitting small flames. It is seen on the 45th floor of the Otherworld Tower, These Rat Hands Hold Back Reality!, serving as the 9th boss of the 10 bosses that the players must defeat as they progress through the dungeon.
There is only one attack the Kingrat can perform:
- Poke - Pokes the player with its sword in order to jab its sword into the player's body.
Some players suggest that one of the main ways to survive this particular boss is by using the "Head Baiter" method, where the players can stand on the head of the boss, enabling them to survive without being harmed if done properly. However, as of the Spring Update, the Kingrat may repeatedly attempt to throw the player off. In addition, if the player is a melee user, this method won't be of much use and instead, the players should use the props found on the platform to their advantage.
- It was introduced in the Otherworld Update.
- Its flame aura that it emits will become weaker as its health depletes.
- It is often compared to the Ratboy's "family."
- It is one of the hardest bosses to fight in the Otherworld Tower simply because it is quite tanky and consumed a lot of the players' time just to kill it. It is also one of many infamous bosses for its insanely high health pool which is greater than Mr.58 itself.
- If you use a Frontier Stargun, it is recommended to circle Kingrat counter-clockwise so bullets are more likely to hit. It is also noteworthy that the Gnome Rocket Launcher is the fastest way to beat Kingrat.
- It is highly speculated that the Kingsguards found on Floor 44 are Kingrat's personal guards.
- The song that plays on the floor is an altered version of the original OST known as "Gwyn, Lord of Cinder."