The Flintstones (1960)
S3E9 Baby Barney
Eager for a slice of inheritance, Fred spins a tale for his wealthy Uncle Tex, claiming he has named his child after him. The catch? Fred doesn’t actually have a son, and with Uncle Tex set to visit, he needs a baby fast! When he can't find a genuine infant, Fred resorts to tricking Barney into pretending to be "Baby Tex."