Gatomon was revealed to be Gabrielle's partner Digimon along with Chuumon, Patamon, and Gomamon. They travel with Gabrielle everywhere even to school. When Gabrielle and her four Digimon partners left for a while. In Gabe and her Pokemon in the Digital World series [see wiki], a young teenage boy calling himself the Digimon emperor started to take over the Digital World using Digimon as his slaves. Gabrielle teamed up with her Pokemon and Digimon to take down the Digimon Emperor. Gatomon was captured by the Digimon Emperor along with Gabrielle's Pokemon, Espeon to make into slaves. But they were rescued by Gabrielle.
Gatomon like her human partner is sweet, loving, kind, friendly, and caring.