Question: Finn (also known as Finn the Human and born as Finn Mertens) is a fictional character and the main protagonist of which American animated television series on the Cartoon Network, and an animated short created by Pendleton Ward? 
Sentence (from "Adventure Time (pilot)"): The short follows the adventures of Pen (voiced by Zack Shada), a human boy, and his best friend Jake (voiced by John DiMaggio), a dog with magical powers to change shape and grow and shrink at will.
Relevant evidence: No