|Friends||Mario, Luigi, Baby Peach, Yoshi|
|Enemies||Baby Bowser, Thwomp, Wario, Waluigi|
|Likes||Mario, Luigi, Baby Peach, Yoshi|
|Hates||Baby Bowser, Thwomp, Wario, Waluigi, The Wizard of Oz|
|Clothing color||Red "M" hat, blue overalls with yellow buttons, red shirt, blue shoes|
|First appearance||New Plush: Baby Mario!|
|Latest appearance||Wario's Clown Scare!|
|Plush Player||Plush Bro 1|
Baby Mario is very sensitive, and cries fairly frequently. However, most of the time, Baby Mario remains jolly, and seems to be the better behaved brother compared to Baby Luigi, as seen in "MLPB Christmas Special 2011: Saving Santa!"
Like his older counterpart, Baby Mario wears a red cap with the letter "M" on it, along with a red shirt and blue overalls. However, unlike his older self, Baby Mario has no gloves and wears blue shoes rather than brown ones.
Baby Mario and Baby Luigi are twin brothers, with Baby Luigi being the younger of the two. The brothers are frequently seen together, and get along well.
Mario is Baby Mario's older counterpart, and acts as a father figure to Baby Mario, though Baby Mario is actually Mario from the past.
Wario is probably Baby Mario's biggest enemy, as he has caused many problems for the Baby Bros. In "Wario's Babysitting Job", he and Waluigi babysat the two brothers, calling themselves "W&W's Babysitting Service". During this video, Wario tortured the Baby Bros, even threatening them and causing them physical pain at some points. In "MLPB Halloween Special 2012: The Haunting of the Wario Bros!", Wario and Waluigi scared the Baby Bros. on Halloween night, dressed as a ghost and a witch respectively.
- As stated in "MLPB Halloween Special 2012: The Haunting of the Wario Bros!" Baby Mario hates the "Wizard of Oz"