"Acchicchi" is a Japanese onomatopoeia or a word which sounds like it is. Here it is the noise you make when you touch something hot or burning.
This Japanese food eraser is a parody of  Morinaga fish shaped crackers similar to goldfish crackers here in the US. On the Morinaga product, there is a picture of a whale saying "Ottotto", which has no particular meaning. On this Iwako eraser, the octopus is saying "Acchicchi".

This Japanese food  eraser is made by Iwako. It comes in the snack eraser collection. The other snack erasers included are , Burnt Octopus, Brat Team Baseball, Chocky, I AM MACHO and Lettuce Child.
This eraser is made by Iwako. It comes in the snack eraser assortment. The other food erasers included are , Burnt Octopus, Brat Team Baseball, Chocky, I AM MACHO and Lettuce Child.