WARNING: OLD artwork
A note before I continue: All my ponies were created for a Generation 1-based fandom. Nothing against FiM, I just prefer the ponies from the 80's, as that was my childhood.
Anyway, This is a character that comes into the story late, (I think,) Ryana. She fancies herself a lock-picking expert and an "Escape Artist Extrodinaire," hence her title in this pic. Her symbol is a bunch of keys on a keyring and a lock-picking instrument of some kind.
She's a dark blue unicorn with light blue mane and tail. Her horn is also short because she's younger than most other unicorns.
MLP and all official characters (c) Hasbro and whoever made the cartoons
Ryana, Escape Artist Extrodinaire (c) Violet Whirlwind