Because you like Granny Weatherwax in Discworld

Albus Dumbledore oversees the most unsafe school in recorded history, with Dementors and giant arachnids run amok. See them in Harry Potter Series.

With his own ship, Peter Quill calls his own shots, and gets to fly from planet to planet blasting '70s pop hits and picking up alien chicks. See them in Marvel Cinematic Universe.

Captain Spock is on a five-year mission exploring the final frontier and boldly going where no man has gone before. See them in Star Trek.

Margo loves mysteries so much that she becomes one. See them in Paper Towns.

A gentle alchemist who is soul-bound to a giant suit of armor, Alphonse Elric is growing into the responsibility handed to him. See them in Fullmetal Alchemist.

Eren Jaeger will erase the Titans from this world until not a single one remains. See them in Attack on Titan.

An aloof punk rock goddess, Nana Osaki has a surprisingly big heart. See them in Nana.

A fearless scientist, Jane won't let a mere shipwreck stop her. See them in Tarzan.

Though Ray Holt is a man of few words and even fewer smiles, he cares deeply about his precinct and detectives. See them in Brooklyn Nine-Nine.

Usagi Tsukino may look like a lazy teen, but when Usagi conjures up her alter ego and calls her Sailor Scout team, no villain stands a chance. See them in Sailor Moon.

Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.

Frank N. Furter is just a sweet transvestite with some not-so-sweet plans. See them in The Rocky Horror Picture Show.