Scumcrabs are a disgusting, evil and scumbaggish variety of the Spycrab. While normal Spycrabs are passive, enjoying to situate themselves in relatively remote areas of the map, such as the 2fort sewers, these heartless creatures take advantage of their opponent's good nature and respect for wildlife. While these may seem like a cruel ruse, put on for the beast's own amusement, it is in fact a complicated psychological maneuver, made to spread their young.
In betraying the ally, said ally then becomes resentful, killing friendly mercs and critters on sight. However, an alternate reaction is how the Scumcrab continues it's evolution: copycats.
Whether it is an impressionable Gibus, a incubating Limescout, or just a rageful friendly, these creatures spread their babies across different maps, different gamemodes, different servers, and eventually different games. They have a snake-like method of gaining public sympathy, too. They'll pretend it was either "self defense" or "a friendly killer", to make the poor victim look like the villian. While not much documents have been written on this abomination of morals, this page lists a small paragraph about their immoral activities.
If anyone has had any first hand experience, whether it's a picture or story, we need to know, so these immoral scumbags can be halted. Good day to you all.