The one and only Immortal on Earth.

Good thing Breakdown checked on him, so Knock Out recovered quickly. The adorable KOBD interactions basically looked like this meme

From chapter 31 of Could Be Worse by @sir-mimkana <3 <3 <3

In Paper Mario: The Origami King, a plot event in Shangri-Spa is Bowser Jr.'s colors disappearing after taking a bath in the Spring of Jungle Mist. When he emerges from the spring, Kamek says a blank text bubble, whereupon he humorously explains that the shock made the color drain from his typeface.

However, while the speech bubble appears blank, it actually has text in it, which is merely set to 0% transparency - "You're bleached!". As such, it cannot actually be seen in-game under any circumstances, and requires extracting the data from the game's files to view. Interestingly, this text has been translated into all languages the game is available in, and cannot be seen in any of them. The table provides the text and a rough translation of all the language versions.

Source: Scrooge200

I conclude that KO sleeps in his alt mode so he can rest worry-free.

so i made breakdown and it only took a few interactions for knockout to fall for him, i'm not even joking 😭

ko has been incredibly patient all this time, while his besties were having marriages every few days 🥺