So I harvesting clay in a Mesa biome for a project, when on the F3 screen there was awfully superstitious lag-filler-upper, whatever they're called, in the right corner of the screen named, 'bossHealth' and 'armor'. They are the same color and I was not wearing armor so the labels must be related. I was on peaceful and when I enabled baddies the pi chart filled 100% with green unspecified stuff. So if you find something DON'T CHANGE IT! Also don't forget to tease Dinnerbone over social media.
"bossHealth" is for rendering the health bar if you're looking at a boss. In your case no boss health bar was needed because you weren't looking at a boss, but the game still has to check that and a small amount of time was used to do so.
"armor" is for rendering the player's armor bar. Again, a small amount of time is used even if no armor bar is actually displayed.
"armor" is for rendering the player's armor bar. Again, a small amount of time is used even if no armor bar is actually displayed.