Blindling

Blindlings are a non-lethal mutation of the Baneling. What they lose in damage they make up for in speed. Blindlings are able to curl themselves into a ball and roll across the battlefield. Blindlings also give off a reddish hue on their exterior. Instead of releasing acid whey they die, they release a thick slime that blinds their target. Blindlings can only cause Blindness upon contacting a player. If a Blindling is killed, even at close range, the necessary chemical reaction to produce blinding slime will not occur, and the Marine will not be blinded.

If the player is alone, or lacks means to restore his vision, he is vulnerable and has almost no means of navigation or defense.

Blindlings rarely travel alone and are usually in packs as part of "Bane Trains." All weapons fair well against Blindlings, but the MP9A2 Sub-Machine Gun and 590A5 Combat Shotgun are the best weapons to deal with groups of Banelings.

Blind
When a Blindling comes into contact with a player, a chemical reaction within their bodies (unstudied due to their volatile nature) causes the Blindling to explode covering nearby enemy units with a thick, opaque, but thankfully inert (compared to the much more lethal Baneling acid) slime. This will blind the affected marine for a few seconds while they attempt to scrape the slime off. Note that the marine is only blind to ambient light; high intensity light such as those given off by flares will allow the marine to see. The Medic's Surgical Laser can instantly evaporate the slime, though the short duration that blindness lasts often does not necessitate the use of a surgical laser unless the situation is desperate.

Tartarus
Tartarus will produce Blindlings, Banelings and occasionally Beastlings as he battles the players. The rate at which he spawns them increases alongside difficulty.

Infestors
When sufficiently damaged, Infestors can become agitated and will lay Zombie Eggs, which hatch into mixed Banelings and blindlings. These can easily catch players off their guard, and will kill multiple players if they stand around the eggs long enough for them to hatch.

Devourers
When killed, a Devourer will release a Baneling and Blindling. These can be very dangerous if one dies next to several players.

Bane Trains
Occasionally large groups of Blindlings will spawn randomly on the map. These "Bane Trains" will contain several Blindlings and at least one Baneling for all difficulties. On Nightmare "Bane Trains" will often also include several ghouls. If blinded it is best to run towards ally positions or away from the direction of the swarm.