http://thejadednetwork.com/sfx/browse/piko_piko/
http://thejadednetwork.com/sfx/browse/peta_peta/
https://www.youtube.com/watch?v=MenPL4HJrk0 - Pikopiko hammer in action
Wonder Yellow's weapon, the Peta Peta Hammer, is modeled after the Japanese-toy called the Piko-Piko Hammer. "Piko-piko" is the onomatopoeia for the chirping sound that the toy-hammers make when struck down on something. "Peta-peta" itself is an onomatopoeia for "stick" as in glueing something, "stroke" as in painting something, and "pressing repeatedly", which is the most likely one for the weapon.
http://thejadednetwork.com/sfx/browse/peta_peta/
https://www.youtube.com/watch?v=MenPL4HJrk0 - Pikopiko hammer in action
Wonder Yellow's weapon, the Peta Peta Hammer, is modeled after the Japanese-toy called the Piko-Piko Hammer. "Piko-piko" is the onomatopoeia for the chirping sound that the toy-hammers make when struck down on something. "Peta-peta" itself is an onomatopoeia for "stick" as in glueing something, "stroke" as in painting something, and "pressing repeatedly", which is the most likely one for the weapon.