He has blonde hair parting to his right with minor freckles on his cheeks, along with green eyes and having his mother’s nose with his father’s face. Leif is 5'3 and has a small build opposed to being scrawny like his father.
Leif wears a Leif wear a black T-Shirt with a dragon on the back of it, with a brown sleeveless vest over it that has fur around the collar, with black pants, and brown boots.
Leif is a brash young man who enjoys fights, riding on his pet dragon Toothless Jr, and just overall being a pest. Leif can however be nice and polite to those he knows but is generally rude to certain types of people; Leif is also devious and has his father's intelligence and way with dragons along with other animals sometimes. Leif is arrogant and can become humble when knocked down a peg or in the presence of a female.
Leif's life has been relatively normal with him being the oldest child of Astrid and Hiccup.
Hiccup Haddock: Leif and his father get along to an extent with Leif learning about the dragons and being the future chief of Berk from his father over the years of his childhood. Hiccup has remarked that Leif is similar to his grandfather Stoick in some ways.
Astrid Haddock: Mother of Leif and wife to Chief Hiccup. Leif and his mother have a good relationship with one another.
Toothless Jr.: Toothless Jr is the son of Toothless Sr and has a good relationship with Leif akin to their father’s relationship.
Alver Haddock: Leif's younger brother whom Leif attempts to have a relationship with only to be ignored or disregarded due to the fact that Alver wants to be future Chief.
Alois Haddock: Leif’s second youngest brother whom Leif had taken on rides with Toothless Jr. around Berk.
Arina Haddock: Only daughter of Hiccup and Astrid, Leif and Arina have the type of relationship Leif wants with Alver.
Hiccup Haddock IV: Newborn brother and son to Hiccup and Astrid. Leif loves his baby brother and promises to take flying one day.
Valka Haddock: Leif's grandmother and mother of Hiccup. Leif has a very good relationship with his grandmother and has constantly asked for more knowledge about dragons from her.
Shenandoah Aiken: Future Love Interest and the next Astrid. Leif and Doe have a bit of history together due to being classmates before going to Ever After High.
Blair DunBroch: Friend of Leif's and Leif has a small crush on her.