The Experiments are bosses encountered in The Foothills. They appear exclusively in E1M10: Creations and are the final boss of The Foothills. The Experiments consist of three separate entities, each with less health than the last. Their boss theme is Departure to Destruction.
The Experiments are dark grey horse-like creatures, that have been modified genetically, as well as cybernetically. The bones of the spine have been replaced by metal counterparts, and all manner of wires have been installed within their body's likely as weight, damage resistance or life support. The eyes have been surgically removed, and replaced with large white crosses, and the face itself has no fur, likely being just skin, bone, or synthetic material. The Experiments also have exposed teeth, and jaws that extend beyond what is naturally possible in equines. The Experiments also have skinless, exposed feet, as well as being covered in five wounds of varying size.
The Experiments' main method of attack is to fire a large volley of fireballs from their mouths. This attack has a wide spread and can quickly kill a player that is standing still. Aside from this attack, Experiments will run around at a high speed after firing before resuming their attack. A good strategy for avoiding their attacks is to always keep moving. It is more difficult for a shot from the Experiments' fire breath to hit a player that is strafe jumping or bunny hopping around them. Strong weapons like the Mortar and Hunting Rifle will quickly dispatch the Experiments, though continuous fire from the Assault Rifle can have the same effect.
Alternatively, if you're feeling especially brave or cheeky, you can release both Experiments at once; due to their large spread of attacks, it is very easy to get them to in-fight, killing one and doing heavy damage to the survivor. The Fast Fire Totem that spawns when the second Experiment is released will let you make short work of their remaining health.