GeGeGe no Kitaro erasers. They have a similar texture to Kinnikuman erasers (muscle man erasers). I think they're from about 40 years ago, so some of them have yellowed a bit. They are old items, so please understand. I did a quick search of past auctions, and while there were similar items, there were hardly any listings for the exact same ones, so I think they are rare. If it's the color variation of the blue Kitaro in the photo, one was auctioned off for around 1800 yen. Another one has appeared, so I'll add a photo.