Two 3D mouse pads have shown up on HobbySearch, with the ad (right) for them claiming "Both the anime and manga are doing really well! From the series Beelzebub, the King's son Baby Beel and maid Hilda appear on 3D mouse pads." These 3D mouse pads have a section filled with gel which elevates part of the mouse pad, creating a "3D" effect, and giving a place to rest the wrist.
For the mouse pad for Hilda, the raised portion is positioned at her breasts, creating the somewhat standard "oppai mouse pad" (breasts mouse pad). However, in something definitely not normal and probably the first male in men's "clothes" version ever, the mouse pad for Baby Beel has his butt as the raised portion, creating a "shiri mouse pad" (butt mouse pad). To quote the 2ch reaction to this one: "Why?" "Is there demand for this one?" The mouse pads are 1890 yen (tax in) each and will be released in August.