Speaking of newcomers in Smash 4, indeed, majority of them had major appearances between Brawl and Smash 4.
- The New Super Mario Bros. series brought them all together for the first time. The moveset revolving around the Clown Car is also heavily inspired by the same series. The Koopalings appeared as playable characters in Mario Kart 8, while Bowser Jr. has been recurring since his debut.
- Major character in Kid Icarus: Uprising.
- Fully-evolved starter Pokémon from Pokémon X / Y.
- His series got rebooted with Punch-Out!! (Wii), where the design also comes from.
- Major character in Fire Emblem: Awakening.
- Miis have been used for Nintendo's hardware since the Wii.
- Series reboot with Kid Icarus: Uprising, being in a similar situation as Little Mac.
- Main player character from Fire Emblem: Awakening.
- Major character in her debut game, Super Mario Galaxy, and having recurring roles in the Mario series since then.
- Protagonist of Xenoblade Chronicles, one of the newest Nintendo IPs and a critically acclaimed RPG. The fact there's a sequel about to release likely favored Shulk's inclusion as well.
- Player character from Animal Crossing, a series that had titles on the Wii and 3DS.
- Wii Fit was a major success on the Wii.
- Though Pac-Man and Mega Man may have had recent appearances, their portrayal is based on their earliest games, so they're kind of retro characters in that regard, hailing back to what made them famous in the first place. Duck Hunt is the token retro newcomer the Smash series always had since Melee.
- Though not a separate character, being relegated as an alt for Olimar, he is still a major character, being the protagonist of Pikmin 3.