Because you like Leonard "Bones" McCoy in Star Trek
A ball of cheerful energy, Pinkie Pie is as sweet as her name suggests and lives to bring others joy with laughter and parties. See them in My Little Pony.
Greg Heffley will be famous someday, but now he's stuck in class with morons. See them in Diary of a Wimpy Kid.
Firo Prochainezo is swept up in a world of mysterious women, alchemists, and rumors of a wine that makes it drinkers immortal. See them in Baccano!.
Orphan Bruce Wayne has a tortured soul, but he's trying his best to weed out corruption. See them in DC Extended Universe.
The Terminator is an emotionless killing machine who won't stop until he's changed the future. See them in The Terminator.
Otis Milburn's mom is a sex therapist, which doesn't help when it comes to being bullied at school. See them in Sex Education.
Kathryn Merteuil may be a vain sociopath, but you won't be able to look away. See them in Cruel Intentions.
Tony Montana makes up for his language barrier with his immense skill at cursing as loud and effectively as humanly possible. See them in Scarface.
Make sure not to anger the Hulk or else he will transform into a giant green monstrosity and smash anything in his way. See them in Marvel Cinematic Universe.
Basically a giant pillow come to life, Baymax is a medical robot created for the sole purpose of helping people. See them in Big Hero 6.
Rukia Kuchiki is a cool and collected warrior who has trouble opening up to anyone. See them in Bleach.