i guess gumball just overfed him until one 일 he grew legs. i don,t really know but they should have an episode where we can see darwin growing his legs.
The is just one episode that is 스플릿, 분할 into two bits Because gumball was ADHA as 4 년 old. He was given Darwin when he was accidently flushed down the toilet. But when he was about to die on dry land gumballs 사랑 for 집 made him evolve into having lungs this is also the reason why Darwin has legs.
