The implication that the Winged Nomu (one of the three Nomu unleashed during the Hosu City incident in the Vs. Hero Killer Arc) is actually Tsubasa—Katsuki Bakugo's childhood friend and bully of Izuku Midoriya—stems from a combination of visual cues, character connections, and creator hints in My Hero Academia. While the series never explicitly states "Tsubasa was turned into the Winged Nomu" in the main storyline, it's heavily implied through subtext, bonus materials, and later revelations about Nomu creation. This has been treated as canon by the fandom and confirmed via author Kohei Horikoshi's extras, with the connection solidified in manga Chapter 259. Below, I'll break it down step by step, including the evidence, how the transformation likely occurred, and a timeline for when it might have happened.

Key Evidence Supporting the Implication

Physical Similarities and Quirk Match:

Tsubasa's Quirk is an unnamed wing ability that grants him red, draconic wings from his back, allowing flight. He's described as a plump child with a rounded face and nearly shaved brown hair.

The Winged Nomu (pale-yellow in color) has bat-like wings for flight, talons on hands and feet, and a gas mask-like covering over its mouth. While the Nomu's appearance is distorted (as all Nomu are grotesque, brain-exposed modifications), the core Quirk is identical: wings enabling aerial mobility. The Nomu's wings are its primary (and only named) Quirk, suggesting it could be the base ability from its original human form.

During the Hosu incident (Manga Chapters 50-59, Anime Episodes 28-33), the Winged Nomu specifically targets Izuku Midoriya, grabbing him and attempting to fly away with him as a hostage. This selective behavior is unusual for Nomu, who are typically mindless destroyers acting on orders. It hints at residual memories from Tsubasa's past, where he frequently bullied Izuku alongside Bakugo.

Family Connection to Nomu Creation:

Tsubasa is the grandson of "Dr. Tsubasa," the kindly doctor who diagnosed young Izuku as Quirkless in Chapter 1 (Anime Episode 1). This doctor is later revealed to be Kyudai Garaki (also known as Daruma Ujiko), All For One's mad scientist ally responsible for engineering all Nomu.

Garaki's reveal in Chapter 259 confirms his alias as Dr. Tsubasa, showing he's been operating under false identities while running hospitals and orphanages as fronts for his experiments. As Nomu creator, Garaki has access to human subjects (often criminals, the deceased, or the vulnerable), and using his own family member fits his ruthless, unethical character—he's shown no qualms about human experimentation.

Creator's Hint in Bonus Materials:

The strongest implication comes from Horikoshi's omake (bonus sketch/commentary) in My Hero Academia Volume 7. Here, the author draws Dr. Tsubasa (Garaki) alongside his unnamed grandson, who has wings identical to Tsubasa's from the flashbacks. The sketch is juxtaposed with Nomu designs, heavily suggesting the boy's fate. This is where the theory originated and was essentially "confirmed" by the creator without spoiling the main plot.

Horikoshi often uses omakes for subtle lore drops, and this one ties directly to the Hosu Nomu arc covered in that volume.

Nomu Lore and Behavioral Clues:

Nomu are bio-engineered weapons created by Garaki using All For One's Quirk-duplication tech. They start as human bases (often corpses or living subjects), which are surgically altered, infused with multiple Quirks, and have their brains reprogrammed for obedience and aggression. Lower-tier Nomu like the Winged one retain some base traits but lack higher intelligence.

The Winged Nomu's death (paralyzed and killed by Stain's Bloodcurdle Quirk after grabbing Izuku) prevents any further exploration, but its focus on Izuku implies lingering subconscious recognition from Tsubasa's bullying days.

How Garaki Likely Turned Tsubasa into the Winged Nomu

Based on established Nomu creation processes in the series (revealed progressively from the U.S.J. Arc onward, with full details in arcs like the Meta Liberation Army and Paranormal Liberation War):

Process Overview: Garaki selects a human "vessel" (body), often from the dead or those he deems expendable. He performs extensive surgeries in hidden labs (like under Jaku Hospital) to enhance durability, add Quirks via All For One's stockpiling, and expose/modify the brain for control. The result is a super-strong, Quirk-augmented monster with no free will. Early Nomu (like those in Hosu) are prototypes—less stable and with fewer added Quirks compared to high-end ones.

Specific to Tsubasa: As Garaki's grandson, Tsubasa would have been an easy target—living nearby, trusting his grandfather, and possessing a useful Quirk (wings for mobility). Garaki likely abducted or lured him, killed him (since many Nomu are confirmed to be made from corpses), and used his body as the base. The Winged Nomu has only one named Quirk (wings), suggesting minimal additions—perhaps just enhancements for strength and talons, keeping the original wings as the core feature.

Motivation: Garaki's fanaticism for All For One and Quirk research overrides family ties. He views humans as tools, and turning his grandson could have been an early experiment to test Nomu viability on someone with a flight-based Quirk. This fits Garaki's backstory as a Quirk-obsessed doctor who faked kindness while building an empire of horror.

No exact "how" details are given in canon (e.g., no scene of the surgery), as it's left to implication for shock value. It's a dark Easter egg highlighting the series' themes of abuse and lost potential.

When It Likely Happened

Timeline Context:

Tsubasa appears in flashbacks during Izuku and Bakugo's early childhood (ages 4-10, roughly elementary school), bullying Izuku and adventuring with the group (e.g., the forest incident in Chapter 1).

The text notes they "parted ways" and lost contact during middle school (ages 12-15). Izuku and Bakugo attend Aldera Junior High without Tsubasa mentioned, implying he disappeared or moved.

The Hosu incident occurs early in the main series (April-May of Izuku's first year at U.A. High, when he's 15-16).

Estimated Window: Sometime during middle school, likely 1-3 years before the series starts (around ages 12-14 for Tsubasa). This allows time for Garaki to experiment, as the Hosu Nomu are "new" but not the first prototypes (the U.S.J. Nomu predates them slightly). Garaki had been creating Nomu for years under All For One, but the Hosu trio were rushed for Tomura Shigaraki's tantrum against Stain.

If it happened post-childhood parting, it explains why Tsubasa vanishes from the story—no one questions his absence, assuming he just drifted away. The transformation must predate Hosu, as the Nomu is deployed there.

Why This Matters in the Story