For those of you who don't know what a narwhal is, look at this page: http://en.wikipedia.org/wiki/Narwhal
For everyone else, there's Master Card....
Though, he may sound like another lame 'Sonic The Hedgehog' character, Jacob is actually from a cmpletely different series of games known as Band Power or Narwhal Blast. (The first game in the series is called 'Band Power! The Legendary Legend Of The Legend That is.... NARWHAL BLAST!') In the series, you play as members of the band 'Narwhal Blast' who go around whacking members of their rival band 'The Hotdoggers' with instruments. Jacob is considered the band's mascot and has the ability to play almost any instrument that he picks up. However, he usually chooses to just dance in the background while the other band members play.
In the Band Power series, Jacob usually isn't a fully playable character. Instead, he serves as an assistant who can drill holes with his tusk and transport the Band Members across bodies of water. Despite this, Jacob is still considered the main character of the series and appears in numerous spin offs as a playable character. (I might even do a Smash Bros. moveset for him...)
Jacob's physical appearence is not like other narwhals. Jacob has hands and feet and is about as tall as an average-sized human. Because of this, he spent most of his childhood working for the circus as 'The Amazing Fish Boy'. It was quite obvious that Jacob did not like his job. One day, when the band's lead singer, Claire, attended the circus, she noticed Jacob's abuse and gave the circus manager everything she owned to set Jacob free.
Jacob didn't want to be free though, he wanted a family that wasn't full of hobos and bearded ladies. So, Claire decided to raise him. When Jacob was in the circus, he didn't know how to play any instruments. So, Claire probably taught him these moves. (Reference to Paula's SSBM trophy as well as Ness and Lucas's Final Smash trophies) Also, if it weren't for that fateful day at the circus 'Narwhal Blast' would have never formed.