I saw that no one's knows about doctor popo so I wanted to talk about him, just to give a few informations : he's a scientist at death&death and he worked with popee we don't know much about him but personal headcanon is that he's actually a good person but he always thinks of money and business first, he and popee have a more different relationship then popee and kedamono, popo is actually able to yell back at popee and throw hands instead of being sweet and like kedamono, i also think that they have similarities like they can both get aggressive, there both not good with calm or rational communication (popo is just a louder version of popee in my opinion) I really wished we knew more about him since we don't have much information(he's literally the least known character) .