|Age|| 16+ (physically)|
|Relatives||Marshall Lee (older brother)|
Marshaleo Scar Abadeer the 4th, more commanly known as Marsh, is the in-universe male counterpart to Marshalia Abadeer.
Marsh looks much like Marshall Lee, having a slim body, black hair and light gray skin. He is also tall, but shorter than Marshall. He has matching pointed ears, fangs and bite marks to indicate that he's a vampire much like his female counterpart. Marsh's hair is slightly longer than his brother's. Marsh wears a blue shirt with matching pants and sneakers much similar to Marsha's with yellow lightening bolt designs on the sides. Like Marsha, Marsh appears to be a teenager.
Like Marsha, Marsh's demon form looks much like horse-like figure. He shares the same colors as Marsha's, but has tufts of fur under his chin like a beard and had floofier hooves.
Marsh is more grounded and level-headed than his brother. Much like Marsha, Marsh is serious and blunt. He shares Marsha's love for reading and fighting. Despite his toughness, Marsh is an actual kind-hearted person.
Marsh presumably has the same powers and abilities as Marsha, such as his advanced combat skills. He also appears to have Marsha's healing abilities when he treat's Fionna's wounds. He also has the same shape-shifting powers as Marsha where he can tranforms into his demon form.
Marshall Lee is Marsh's older brother. Unlike their female counterparts, Marshall and Marsh's sibling rivalry is more calmed down. Marshall often messes with Marsh, much to Marsh's annoyance.
Marsh and Fionna are good friends, with Fionna having a crush on Marsh. Because of his serious nature, Marsh doesn't exactly flirt with Fionna but rather his looks have been known to stun Fionna. Marsh treats Fionna much like a guy and treats her no different than how he treats his brother.
- Marsh has many similarities to Marsha, as Marsha told the story in "The Demon Prince".
- Marsh is refered to as the Demon Prince, much like how Marsha is refered to as the Demon Princess.
- Marsha and Marsh's demon form are much sinilar in appearance with minor alterations with Marsh's form to make Marsh's form look "manly".
- It is presumed that Marsh is a Nightosphere gladiator like Marsha.
- Marsh is misnamed as Marshall Leeroy by the Ice King.