Bert's 'Sesame Street' pal is Ernie, a five-letter character who has been a part of the show since its debut in 1969. Ernie is a lovable, cheerful, and mischievous puppet who often gets into trouble with his best friend Bert. He is known for his silly antics and catchphrases, such as 'Oh, boy!' and 'Surprise!' He is also an accomplished musician, playing the saxophone and singing duets with Bert.