Lynn Loud Jr. is the male version of Girl Lynn Loud.

1. Appearance: Boy Lynn looks exactly like the Girl Lynn. The only difference is that his hair is shorter, his red and white jersey shirt has the number 0 on it, the sleeves of his jersey are shorter along with his socks, and his shorts are longer.
2. Personality: Boy Lynn is quite similar to Girl Lynn but is a lot meaner, dumber, and he is an inconsiderate bully who doesn't care if anyone gets injured or potentially killed. He is also sadistic and laughs at everyone's pain, including his own pain. But in the universe with Linka Loud, he's shown to be very caring and protective towards his sister.

Trivia:

1. Not only is Boy Lynn similar to Girl Lynn, but he is the only older brother to be voiced by the same actor.
2. Much like their female selves, he and Lars both share the same voice actress.
3. Boy Lynn is the only male Loud child to share the same name as his female counterpart, since "Lynn" is technically a unisex name.
4. Lincoln thinks he's the only brother who's exactly like his female counterpart Lynn.
5. His Polish name is Hektor.
6. He is the only brother who isn't accredited on the Brazilian dub credits.
7. Boy Lynn is Latin American dubber Monserrat Mendoza's first male role.