If you jumpslash after you hookshot onto them you'll get hurt by them. You can also do this as Kid Link. You need to jump on the left hand and run over to her arm and sidehop up it, now jump down at the right angle and you'll get hurt by them.

Also Nintendo probably put this in for a joke. Like how you dump out a fish into the cutscene where you learn Saria's song and the fish will appear on Saria's lap during the cutscene.