Instead, Popplio walk on land using all four flippers and front flippers to swim on sea. People even stopped yelling at the poor little seal that was just doing his best, eventually. While Litten use four legs to walk all time and Rowlet are bipedal, Popplio are neither bipedal nor four-legged Pokémon. From the second that we saw the three Sun & Moon starters, we knew that we had something special on our hands.
Rowlet begins as a Grass-type and flying-type hybrid, but after it's evolved twice it drops its flying-type in favour of being a ghost.