Ma-Ti is the fifth Planeteer to be summoned. He is from South America, and has the power of Heart. He receives his ring after rescuing Suchi from a jaguar, who then presents the Ring of Heart to him.
Ma-Ti is an orphan, as learned in the episode "A Mine is a Terrible Thing to Waste Part I". His parents were killed during political unrest, but Ma-Ti does not believe they died in vain, as the issues they were fighting for soon resolved as a result of the awful night the village was attacked.
Ma-Ti is the youngest and smallest of the Planeteers, at 12 years old. He has shoulder-length black hair, olive-tan skin and dark brown eyes. He is also apparently scrawny, which explains how he is able to climb around like his monkey partner in benefit, Suchi.
His main outfit in the first 5 seasons consists of a sky blue Planeteer sleeveless shirt (with a green globe emblem on it, much like Kwame's does) under a khaki vest, a black belt, brown shorts, and teal and red high top converse sneakers. He also wears two armbands on each arm, one of which has two red, yellow, and green feathers, and two blue necklaces and a blue neckpiece around his neck. In Seasons 3-5, he abandons the necklaces and now wears only one armband.
In the final season, Ma-Ti wears a yellow sleeveless Planeteer shirt with a green emblem under a red vest, gold shorts, white ankle socks, and brown high top sneakers.
- It's been strangely known for quite some times over the years that fans believe that he bears a strong resemblance to a younger character of another TV show named Carlos Ramon from Scholastic's The Magic School Bus.