Bossy Little R

"I know a dude who's bossy and rude His name is R He's a bossy little dude And if he stands behind? A, I, or U He changes the way they sound It's true If you change the last letter of CAT to an R The A turns from AH to AR CAR If you change the last letter of SIT to an R The I turns from IH to IR SIR If you change the last letter of FAT to an R The A turns from AH to AR FAR If you change the last letter of FOX to an R The O turns from OH to OR FOR If you change the last letter of SIT to an R You get SIR Cause he's a bossy R If you change the last letter of FOX to an R You get FOR Cause he's a bossy R If you change the last letter of FUN to an R You get FUR It's that bossy R If you change the last letter of HEN to an R You get HER It's that bossy R"