Doppler and Amelia's children are minor characters in the 2002 film, Treasure Planet. They appeared only at the end of the movie. A certain time after their mutual spatial adventure with Jim Hawkins, Captain Amelia and Dr. Delbert Doppler plausibly are finally married and becomes parents of four babies: three daughters (with anthropomorphic felide aspects like their mother) and a son (with anthropomorphic canide aspects like their father).
Comically, the daughter who is most similar to Amelia, enjoyed to annoyed her brother, reminiscing the old banter between their parents when meeting for the first time.
It induct that it is a same reproducing specie (and not two distinct species) where the females are cat and the males are dogs.