What a wonderful ninja Turtle
Latex would be better !!
I wouldnt use Expanding foam for anything to go against the skin .
Its fairly toxic and gasses off for a long time, read the Data sheet on it
https://www.smooth-on.com/msds/files/FlexFoam_It_Series.pdf
Gosh no wonder I don't sew on commission. Have to be in the mood and that's rare.