Where does “mousefucker” come from?

mousefucker (English) comes from English fucker, from English -er, from Middle English -er, from Old French -er, from Latin -āre, from Proto-Italic -āō, from Proto-Indo-European -eh₂yéti, from Proto-Indo-European -yéti — he, she.

Ancestry of “mousefucker”, step by step

mousefucker traces back through two separate lines of ancestry.

via English fucker

StepLanguageWordMeaning
1EnglishfuckerAn undesirable person; The object of some effort;...
2English-erA person or thing that does an action indicated...
3Middle English-eragentive suffix; agent noun suffix
4Old French-erAlternative form of -ier, verbal suffix;...
5Latin-ārefirst conjugation
6Proto-Italic-āōForms primarily denominative verbs
7Proto-Indo-European-eh₂yétiCreates iterative/ frequentative/ intensive...
8Proto-Indo-European-yétiCreates intransitive, often deponent,...
9Proto-Indo-Europeanyé-
10Chichewaiyehe, she

via English Mouse

StepLanguageWordMeaning
1EnglishMouseThe Walt Disney Company
2Germanmausmouse (animal)
3Middle High Germanmūsmouse
4Old High Germanmūsmouse
5Proto-West Germanicmūsmouse
6Proto-Germanicmūsmouse
7Proto-Indo-Europeanmúh₂smouse
Every word from Chichewa iyeEvery word from English -erEvery word from Proto-Indo-European -yéti