Lucas and Derpy are best friends. He got her on his 14th birthsday as a pet, but she was even more than a strange gray cute pony-like creature who can speak. Derpy has a secret ability to grow when she really concentrates. The two of them spend all time together, but the teenager boy has some bullies at school, who try to make fun of him.

When Lucas and Derpy are going for a walk to the park, the bullies suddenly show up and start terrorizing the boy and the "ugly squint dog". But when Lucas gets to the ground, Derpy gets angry and becomes a real giant.

Picture from Rotzerrich from DeviantArt

This story is a sequel to You're Not Fine

Friendship is a give-and-take relationship. Fortunately for you, Pinkie doesn't ask for much, and she has plenty to give.
Maybe it's time to start giving back.

Friends are there to make memories, to love, to respect. Pinkie Pie knows this better then any pony, and she's been trying for so long, to go beyond that. Through trials and misfortune, she'll keep going as long as her big heart keeps beating; because for her, some things are more important, then any friend could ever be.