Below are the head canons for Loki in the four verses he can appear in:
Has a high level of pride, up to the point where he will not apologize for his past sins. Given the time, however, he might end up asking for forgiveness.
Speaks frankly and can sometimes say hurtful things, although on hindsight he does not mean to.
Can be irritable, especially if someone other than Jane or Linus interrupts him during one of his activities.
Wavers between the "good" side and the "bad" side, as his position within S.H.I.E.L.D. tests his patience.
Obsessively overprotective of Jane; he would never admit that she has become his source of strength and weakness.
Can act childish (although this is very rare), such as when he teaches Linus magic and pulls pranks.
Has a sweet tooth (secretly devours strawberries and chocolate by the pound).
Fathered a son, Linus, with a Midgardian woman whom he met a few decades prior to the events of Thor.
Maintains a civil relationship with his daughter, Hela.
While he calls the God of Thunder “Thor” in public, Loki occasionally slips and calls him “brother”; this shows that he still considers Thor as his kin.
Owns an iPod, which he is fond of throwing whenever he dislikes a song.
Has been reinstated as King of Jotunheim, but stays in Midgard for Jane’s sake.
Goes on various missions for S.H.I.E.L.D., but prefers to work alone.
Likes the silence and solitude, but won't say no to an sudden visit to Isabel's or a movie marathon, where he ends up hogging the entire couch.
Very bitter, especially towards his 'family'.
Easily angered, but this is hardly noticeable as he keeps a straight face throughout.
Prone to psychotic tendencies, and will not stop short of planning to kill Odin.
Hides his fear and sadness behind these said traits.
Feels true remorse for his actions, but does not openly admit it due to his wounded pride.
Spends most, if not all, of his time reading. Frigga provided him with several books in order to help him pass the time.
Plagued by nightmares of his deeds in Midgard, and is constantly haunted by The Other’s threat that Thanos will find him and make him “long for something as sweet as death”.
Escapes the confines of the prison occasionally; leaves a clone behind so as not to arouse suspicion. These frequent trips gives him knowledge of Malekith and his forces.
Ruthless to his enemies and generous to his family and friends.
Has a strong sense of loyalty and takes betrayal very seriously.
Cold and unflinching to the rest of the world, but warm and loving when in the presence of his family.
Values family above all else; is known to have murdered his younger sister’s boyfriend when the youth left her pregnant.
Is skilled with a number of weapons, particularly the katana and Glock. Despite this, he prefers having his minions do the killing, so as to not get his hands dirty.
Is a popular philanthropist. His mafia connections are only evident when he encounters any of the members of the Romanoff, Odinson, and Banner crime families.
Maintains a gentlemanly demeanor, which was instilled in him by his mother, Francesca. However, he also has an uncontrollable temper that he inherited from his father, Cyrus.
Loves joking around with both friends and new acquaintances.
Business-like when dealing with customers.
Light-hearted, but can be devious and revert to his intimidating personality when he feels like it or feels threatened.
Generally more friendly than he was since under Thanos's spell, but chooses his close friends well.
Likes collecting priceless (and magical) objects for a living. Sells them to interested collectors, but only gives the price upon request.
Goes on coffee runs regularly, and his favorite blend is black coffee with two sugar cubes and a splash of milk.
Enjoys watching movies, save for family-themed and animated films.
Loves practicing whatever magical abilities he has and lives up to his name as the God of Mischief (albeit in mortal form).
Chose to become mortal rather spend an eternity in the Asgardian dungeons.