Sloth

Sloth (スロウス, Surōsu) is the name given to two very different Homunculi due to the sheer differences between the 2003 anime and the manga.

In combat, Sloth uses his fists and the chains on his wrists coupled with his astonishing physical strength. He is more than capable of crushing and tearing through solid rock and steel with his bare hands, and can easily crush a human body with accidental ease. Sloth's hide is also extremely tough, rivaling Greed's carbon skin in durability, although it is much more flexible and seems to be a permanent feature of his body. Nothing short of tank or artillery fire could pierce it from a distance. In his most devastating attack, he hurls himself towards his foes at incredible speed. In fact, his speed is so formidable, he appears to have no means of controlling his momentum, and is thus incapable of stopping himself without crashing into something. He claims to be the fastest homunculus, which is ironic as the definition of sloth is being slow or sluggish. However, he is extremely clumsy and not very bright as he is easily fooled. He is also not very accurate in attacking.

His regenerative abilities are notably slower than those of the other homunculi though the reason for this is unknown. It is in line with his sluggish character, and may be an effect of his large frame. He is able to use this to his advantage however, by stretching out the tendons in his muscles, increasing the range of his attacks. It should be noted that Sloth did not need to be killed as many times as his brethren, because when Alex Armstrong impales Sloth through the mouth with an earth spike as Sloth charges, his philosopher's stone lost a lot of energy to keep Sloth alive while Sloth tried to get rid of the spike. This must have done a lot of damage because the Armstrongs only had to kill Sloth a few more times before he disintegrated. Some of the Stone's energy may also have been lost keeping Sloth alive while he was frozen in a snowdrift outside Fort Briggs, as it was a fairly long time before he was thawed out.
Sloth is tasked with digging a gigantic transmutation circle beneath Amestris to be used in turning the country into a Philosopher's Stone. Though he is briefly impeded in this job when he runs into the Elric brothers at Briggs Fortress, he is allowed to continue his work, finishing the circle in chapter seventy-eight. Just as his name, Sloth is always wanting to rest and finish his job so he can stop working. When Greed is captured by Wrath, he asks about Sloth and Lust answers saying he is still working, meaning he was already making the tunnel before Greed left the group one hundred years before.
Olivier stabbing Sloth in the head.
After finishing the transmutation tunnel, he acted as Father's personal bodyguard, following him when he took direct control of the army and sleeping near Father's throne when he has nothing else to do. In Chapter 91, he was sent to deal with Major General Olivier Armstrong when she took one of the corrupted generals of Central as hostage, killing the hostage in a surprise attack. After a lengthy battle with the two Armstrong siblings, in which Sloth gets impaled several times, Izumi and her husband, Sig, come to help aid the Armstrongs. Sig and Alex Armstrong then proceed to attack Sloth, and finally they throw Sloth onto an earth spike, impaling him. As he attempts to recover, his arms begin to quickly disintegrate. Realizing his death forthcoming, he embraces his end with a smile, stating that merely living was too much effort for him, making Sloth the 4th Homunculus to die.

Last Words: "I'm gonna die? Gonna die...what is dying? Thinking about it is annoying. Living on....is also annoying..."