Inspired by the articulating trex, I created this articulating shark (which I felt was a more natural animal for the articulating motion).
Strong links should be relatively kid safe.
Printing at 50% infill will result in a strong toy like endurance.
I wouldn't print lower than 0.15 layer height (without scaling) on account of the hinges.
Recommend a 1mm wall and ceiling/floor thickness, this results in solid links.