His name is Desmond, he was made as a means to allow Mewtwos to be able to breed, but he was ultimately defective, resulting in a Mewtwo who was both perpetually pregnant and unable to give birth to Mewtwos (any pokemon conceived by him will only be the same species as the partner). One positive thing though is that even though he's unable to conceive his own species, any pokemon birthed by him will have a higher chance of having the best IVs along with higher Shiny odds (think breeding with a Shiny Ditto in Gen 2 odds)