Does anyone know how Darwin grew his legs?

i guess it happen not really sure :-_

i guess gumball just overfed him until one day 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 split into two bits
Because gumball was ADHA as 4 year old. He was given Darwin when he was accidently flushed down the toilet. But when he was about to die on dry land gumballs love for home made him evolve into having lungs this is also the reason why Darwin has legs.