Tuck is a four-year-old Red Eared Slider terrapin boy. He is described as sensitive with an emotional connection to living things and the heart of the group. As a superhero, he wears a white French sailor's cap, blue Aquasocks, and a red cape. He is voiced by Teala Dunn in the United States version, and Catherine Holden in the UK version. Tuck is empathetic, often desiring to give the rescued animals a hug or keeping them company while Linny and Ming-Ming put their rescue plan into action. He also has keen observational skills, spotting things from a distance, which often garners him the compliment, "Good eye, Tuck!".
Tuck has green skin and a dark green shell. His eyes are blue with black pupils. Tuck's hat is similar to that of a sailor - white with a blue stripe and a red top. He has two blue sneakers and a red mouth. His cape is red with the Wonder Pets' logo, a big red 'W', on it.
Tuck has a cousin named Buck. In Tuck and Buck!, Tuck is jealous of his cousin's skateboard skills. After most of the episode, Buck realizes how boasting is wrong and caring about friends and family is right.
- Although Tuck is a male, he is voiced by a female human in both the US and UK versions of the Wonder Pets! series.
- Tuck is the only male in the Wonder Pets team.