Because you like Legolas Greenleaf in The Lord of the Rings

Prideful and psychotic tendencies combine to make Dr. Eggman a dangerous and villain who will squash anyone in his path. See them in Sonic the Hedgehog.

You wouldn't know it by looking at her, but beneath Sheila Jackson's sweet, motherly exterior lies a sex addict. See them in Shameless.

After alien Haruko rides in on her Vespa, giant robots spouting from Naota Nandaba's forehead soon become the least of his worries. See them in FLCL.

After becoming accepted into the group of popular girls, Tracy Freeland has turned from a sweet and reserved teenager into a monster. See them in thirteen.