This is a great activity for kids.

Mix together 1/4 c. wood glue and 1/4 c. liquid starch in a bowl. Add
a few drops of food color. Stir. It will start to solidify quickly
but it takes about 10 minutes until it stablizes. Store in a ziploc.

This is non-toxic according to the local tv station but wash their
mouth out good if they get it in there(I can't imagine it tastes very