Signs warning of imminent personal injury almost always include animals here in Japan. The subways show cats getting their tails caught in the door while rushing for the train, anthropomorphic dogs warn of the danger of being hit by your neighbor's backpack etc.
I spotted another example of this puzzling trend in Hibiya. Be careful of the door, the sign says. But the picture seems to add "lest our ELEVATOR ATTACK CRABS leap out and slice your finger off!"
