"Super Smash Bros. 4" is almost a year-old after its release last year, however, the game still continues to be exciting and fresh due to Nintendo's frequent DLC updates.

Nintendo recently announced that they will not be releasing "Super Smash Bros." annually, but will instead focus on releasing DLCs to improve the current game.

In the update released last month, players were thrilled with the addition of four new characters: Mewtwo, Lucas, Roy and Ryu.

Recently, it has been speculated that three more characters will be included in the roster, specifically Shovel Knight, King K. Rool and Professor Layton.

According to a credible Nintendo Life source, Yacht Club Games' "Shovel Knight" may soon be added to the roster. Shovel Knight, the famous video game character released only last year, will also be getting an accompanying Amiibo figure.

Speculations were further fueled when Yacht Club Games announced that they will be joining Nintendo during their PAX Prime pre-event. The developers have announced that they will be announcing a collaboration with Nintendo this week.

Nintendo will be present at the PAX Prime event, to be held this Aug. 28 to 31, and will be setting up game kiosks with "Super Smash Bros."

It's possible that Nintendo and Yacht Club Games could announce the inclusion of Shovel Knight in the "Super Smash Bros." roster during the event.

Gamnesia also reported that Nintendo has recently trademarked the name "King K. Rool" recently. The "Donkey Kong" character has not appeared in any game since 2008. Thus, it was also rumored that character may be joining the roster. 

Professor Layton may seem like an unlikely choice for a "Super Smash Bros." fighter, but Attack of the Fan Boy has revealed that his addition could be likely.

The rumor of Professor Layton's inclusion started when Christopher Robin Miller, who is the voice of Professor Layton, was credited in IMDB for the "Super Smash Bros." Miller revealed in his Twitter account that he had done additional voice work for his character, but was unaware for which project it would be used.

He later reiterated that Nintendo would be the only one who could confirm this speculation.

It would be fun to see these three new characters added, however, it should be noted that at this point, everything remains a speculation.

The good news, however, is that there will definitely be one new character added to the roster.

Nintendo's Smash Bros. Fighter Ballot is still ongoing until Oct. 3. Through the voting poll, fans can nominate one character that they wish to be added to the roster. Results will be revealed after the poll closes.