YouTuber and Emergency Room (ER) Doctor Jordan Wagner reacted with shock to a series of extreme body modifications he witnessed on his channel, and warned against anyone getting their eyeballs tattooed.

Wagner, who boasts a whopping 2.41 million subscribers on his YouTube channel, is known for his popular "ER doctor reacts" series, where he watches various medical clips and gives a running commentary on them.

One such video shows him reacting viscerally to a clip of body mod enthusiast Tiamat Legion Medusa, who transformed themself into the world's first "dragon person."

Initially shocked but not concerned about their implants, Wagner comments that subdermal implants are "inert" and actually not so uncommon, especially in the butt and breasts.

When it came to Medusa's eye tattoos, however, Wagner was not so enthusiastic, warning that the color of a person's sclera (the white of their eyes) is used to diagnose many illnesses.

"The sclera is helpful – if it's really red, you can see if there's a hemorrhage, you can see if it's turning yellow, it might be related to someone who's got liver disease," he explained.

"So when somebody has modified [the eye], it actually makes it more difficult when there are potential medical problems going on."

Wagner goes on to warn that major tattoos run the risk of cellulitis and, in more severe cases, can result in necrotizing fasciitis, leading to the need for skin to be medically removed.

Ultimately, Wagner expresses sympathy for Medusa, ending the video by wishing them the best and hoping that they made their body modification under supervision with medical professionals.

"Different traumatic events in our lives lead us down different paths, and what I hope for this individual is that everything's done safe," Wagner said.