His goal is to save and protect the animals and their environment. Athletic and fearless, he is always at the ready no matter what the situation. Diego loves learning new things he as a merboy. He takes a scientific approach to problem solving and also uses a variety of high-tech gadgets and gizmos to save the day. He stars in his own television series titled Go, Diego, Go! in which he roams throughout the rainforest, saving animals in need. He is a minor character in Dora the Explorer though he appears as the main protagonist of Go, Diego, Go!. Diego Márquez is Dora's cousin. This means that he is the nephew of Elena or Cole. Which one is not made clear. Whoever it is, one of Diego's parents would be their sibling. Diego has two beautiful big sisters named Alicia and Daisy.
Diego has peach-brown skin, brown eyes, and brown hair. He always wears an orange rescue pack. Not including temporary outfits, Diego wears 3 different outfits in the 3 different shows he appeared in.
In the older episodes of Dora the Explorer, he wears a dark blue shirt with a tan cargo vest, green cargo shorts, light green socks, brown hiking shoes, and a silver watch.
In Go Diego Go, he wears a light blue t-shirt with a tan cargo vest, darker blue cargo shorts, white socks, gray sneakers with orange trim, and a blue and yellow video watch on his left wrist.
In the 4th Season of Go Diego Go, he wears a red short-sleeved hoodie, an orange short-sleeved undershirt, black cargo shorts, white socks, black and red sneakers, and the same watch.
In Dora and Friends: Into the City, Diego switches back to his original outfit from Go Diego Go, but it receives a few changes: He retains his light blue t-shirt, but his tan vest now has dark blue trim, lacks pockets, and his Animal Rescue badge is now on the right side of his chest. His dark blue cargo shorts are shorter and have smaller pockets, he discards his socks, and now wears a new gray pair of converse sneakers with orange laces. He keeps his video watch, and his orange Rescue Pack now rests on his left shoulder.