My reason is that they didn't cook any meat so they ate alot of raw meat which probably got them sick alot of times but there faces probably adapted to raw meat
I think the newborns would be small since there baby's and the other newborns should be small to cause there also babys and they should have normal body parts to and cave tubby should have normal arms and legs
Make a video of all the characters fight with shutter all the characters you put down right now make them fighting shredder make them fight all of everybody everybody that's you you can put your part in down everybody on the map you can put down put them old down and make them all face then put everybody else then do then do it and do it twice and then fight
