In Quake console command "showturtle 1" will show a little turtle icon in the top left corner of the screen when frame rate drops below 10 fps.
@dosnostalgic@mastodon.socialIt was actually a part of QTest where it's impossible to turn off.
The turtle icon is present in Quake 2's PAK0.PAK file, this time in PCX format. The game has a scr_showturtle CVAR that defaults to 0. But there's no source code associated with it other than checking its value. Retail release (original 3.05 or latest 3.21) doesn't draw a turtle. 
@dosnostalgic i rather vividly remember this from running quake on some less than amazing hardware.
@dosnostalgic Funny that this HUD font is in QTest but then later reappears in Quake 3 Arena
@bristle Huh. I've never noticed that till now.
@dosnostalgic I caught the last post of this first and thought it was about a LOGO parser hidden in Quake and got excited for a moment.