At the start of Deku's Hero Academy journey in My Hero Academia, a routine exam is interrupted by a League of Villains attack. The villains were easily pushed back, but they brought with them a secret weapon: a monstrous creature known as "Nomu." Although they seem to be minor antagonists, every Nomu appearance makes major waves.
Nomu are mindless, artificial creatures created by Dr. Kyudai Garaki from the bodies of deceased villains and heroes. These corpses have been modified to hold and wield multiple Quirks at once, making them powerful monsters and serious threats. All for One originally gave the Nomu their multiple Quirks but, since his defeat and capture, Dr. Garaki now uses an advanced surgery to physically transplant the Quirks into them - a much less discreet procedure that requires a lot of time for the Nomu to stabilize.
Types of Nomu
Currently, there are four different grades of Nomu, identified according to their physical enhancements and the number of Quirks they possess.
LOWER-TIER
The lowest level of Nomu in My Hero Academia are still strong enough to overpower some Pro Heroes. They are usually light in colour with enhanced physical strength and one or two Quirks. They are generally used as foot soldiers and expendable minions. However, they only attack when given a voice command from their designated superior.
MIDDLE-TIER
Middle-Tier Nomu are only slightly stronger than the Lower-Tier. They possess more Quirks and can produce the physical changes those might bring, like wings, for example. Middle-Tier Nomu have a range of different body colors but, beyond that, they've only been seen a few times, so not much is known about the upper limits of what they can do.
UPPER-TIER
An Upper-Tier was the first Nomu to be introduced in My Hero Academia, appearing alongside Tomura Shigaraki and Kurogiri during the assault at the Unforeseen Simulation Joint (USJ). Its attack at the USJ had a heavy impact on the Hero Academy and the Nomu even managed to injure the great All Might. The Upper-Tier Nomu are powerful enough to fight or even defeat top Pro Heroes, like Eraser Head and often have Super Regeneration among their cache of Quirks. Their pitch-black bodies and bird-like faces make them distinct - and terrifying.
HIGH-END NOMU
This type of Nomu far outclasses the others. High-Ends often retain some of their human personalities and are able to talk, think and analyze an opponent's power to pinpoint their weakness in battle. Their strength is far superior to other Nomu, they can have up to six or more Quirks and they can even store some low-level Nomu inside their body to release as weapons against opponents. These Nomu are created from the bodies of exceptionally powerful villains with tremendous effort through surgery. However, they need more time for activation and stabilization compared to the other levels. The drawback is worth it, however, as High-End Nomu can completely overwhelm multiple top Pro Heroes at once.
Impact On the Series
In My Hero Academia Season 4, a High-End Nomu known as Hood debuted. Powerful and intelligent, Hood created an uproar in the city, though it only seemed to show interest in fighting powerful heroes. In fact, the Endeavor, the No. 1 hero, only narrowly beat the Nomu, and needed significant help from Hawks, the No.2 hero. Even then, Endeavor was heavily injured in the battle.
However, Hood is just the latest in an series of ever-escalating Nomu attacks. When Nomu of any grade appear in the series, their presence is felt. From wounding high level Pros to putting greenhorn students on the ropes, the League of Villains' army of monsters are certainly nothing to balk at. And, with Dabi's recent discovery of twelve High-Ends in a laboratory, Nomu encounters are set to become even more dangerous.