Cow: Hmmm-hmm-hmmm ... (he looks up and reads the sign) 'I know I am a (coe).' ... That doesn't sound right. (A farmer comes in, grumbling) Farmer: Mumble-mumble -- You're not a coe, you're a cow! Cow: (brightly) I get it! Hmmm-hmm-hmm -- 'I (now) I am a cow!' Farmer: (walking around, the cow looks confused) Grumble-grumble-grumble ... Listen -- 'I KNOW I AM A COW.' Cow: (smug) You're not a cow!
https://primoaccordo.net/sesame-street/i-know-i-am-a-cow.htm