“Sometimes you look in a field and you see a cow and you think it's a better cow than the one you've got in your own field. It's a fact. Right? And it never really works out that way.”

“I never saw a purple cow,
I never hope to see one;
But I can tell you, anyhow,
I'd rather see than be one!”

“I don’t have to do nothing you say, you old heifer cow. And you are old. Really, really old. And a cow, too. (Simi)”

“Facts are like cows. If you look them in the face long enough, they generally run away.”

“You should never hesitate to trade your cow for a handful of magic beans.”

“Nerds do not think they are better than you. Nerds are better than you, in their particular fields, unless you happen to be an even more devoted nerd.”

“I could dance with you till the cows come home. Better still, I'll dance with the cows and you come home."
Groucho Marx was never one to pass up an opportunity for a play on words and this occurs in his dialogue of the 1933 film Duck Soup:”

“Interviewer: In other words you were born with your destiny tied to cows. So, of course you must love cows?”

“To my mind, the only possible pet is a cow. Cows love you. They will listen to your problems and never ask a thing in return. They will be your friends forever. And when you get tired of them, you can kill and eat them. Perfect.”

“If you think you are emancipated, you might consider the idea of tasting your own menstrual blood - if it makes you sick, you've got a long way to go, baby.”