YOU SAID:
I have a pet cat who eats fish
INTO JAPANESE
私は魚を食べるペットの猫がいます
BACK INTO ENGLISH
I have a pet cat that eats fish
INTO JAPANESE
私は魚を食べるペットの猫がいます
BACK INTO ENGLISH
I have a pet cat that eats fish
That didn't even make that much sense in English.