Bioshock crossover 

Rarity's been getting busier and busier, leaving Sweetie bored and alone while at the boutique- that is, until she meets a creature...one that won't stop following her around...but, she's harmless...right? Right?

Link to whole coverart: http://skeezix78.deviantart.com/art/Sweetie-Belle-s-Big-Sister-455926505ga_submit_new=10%253A1405525371&ga_type=edit&ga_changes=1