Abnormality #0009, codenamed "Overlay Bleed," refers to a rare condition in which the in-game heads-up display (HUD) begins to desynchronize, duplicate, or smear across the screen, affecting the gameplay interface in subtle but escalating ways.
This phenomenon begins innocuously with:
Health, Suit, and Ammo counts begin to duplicate and smear across the screen.
Crosshairs slide slightly out of alignment.
Weapon viewmodels begin to disappear.
Over time, players will see portions of the HUD - like the kill feed, scoreboard, and chat box - persist on screen, even after closing menus or dying. Text may repeat itself, stretch diagonally, or "ghost" in multiple layers. The effect builds until the entire interface becomes unreadable or overlays onto the world itself - appearing on walls, props, and NPCs.
Documented on May 5th, 2018 during a multiplayer sandbox session using the custom HUD addon advanced_hudmod_2.3. One player's interface began duplicating after switching rapidly between tools, eventually causing the kill feed to persist at the center of the screen even after respawn.
Upon relaunching Garry's Mod, the distorted HUD remained for two sessions, despite all addons being disabled. Players began calling the effect "Overlay Bleed" due to the way the HUD appeared to seep into the game world.
Overlay Bleed slowly began to pass into myth as hud mods began to update and/or new addons came out that rendered those infected with Abnormality #0009 obsolete.
Excerpt of 0009 manifesting and pasting the health hud over and over again. Despite the original hud being transparent, it uses a still image of when it started to manifest