Experiments can be found in the Experiment Cave, which can be accessed during Creature of Fenkenstrainquest. Completing the whole quest is not required to kill them, as you can simply push the farthest memorial from the castle and you will enter finding quite a few of them. In total, there are 18 Experiment spawns in the cave: 7 Sheep-dogs, 5 Spider-men and 6 Wolf-women.
The Wolf-woman may only be killed once (unless you drop the cavern key obtained by killing it) during the Creature of Fenkenstrain quest. Attempting to kill one afterwards results in the message "You don't have the heart to kill the poor creature again."
An Experiment must be killed to complete the "Lab Clean-up Assistant" Morytania task.
The Sheep-dog experiment may refer to the saying "A wolf in sheep's clothing", or possibly a sheep dog.
The Spider-man experiment might be a reference to Spider-Man. It also closely resembles one of the mutant toys from the Pixar film Toy Story.
Before the Evolution of Combat, experiments were popular for combat training as they had 1000 life points with a combat level of only 25.
Experiments have not had a graphical update since their release, and they still use the old sounds for wolves and spiders when in combat.
Even though the experiments are crossed between two monsters of different races, like sheep and wolf, they still drop regular bones.
The head of the Spider-man appears similar to the old default head of a male player character.
The head of the Spider-man also closely resembles the old graphic of dwarves. If it is indeed a dwarf head, it may be a parody reference to the dwarf-spider, a very small spider that is found in both the USA and United Kingdom (In the UK it is more commonly known as the money-spider).