YOU SAID:
a flabbergasted donkey eat my brother
INTO JAPANESE
びっくりしたロバが私の兄弟を食べてしまう
BACK INTO ENGLISH
Startled donkey eats my brother
INTO JAPANESE
驚いたロバが私の兄弟を食べる
BACK INTO ENGLISH
Surprised donkey eats my brother
INTO JAPANESE
驚いたロバが私の兄弟を食べてしまう
BACK INTO ENGLISH
Surprised donkey eats my brother
That didn't even make that much sense in English.