Gubby

(adj./n.)
Describes someone or something that is unintentionally funny or clumsy in a silly, endearing, or "dumb dog" kind of way. Often used to affectionately highlight an individual's goofy charm or playful ineptitude.

(adj.)
"He was the most gubby of them all."
"Her gubby antics always made everyone laugh."

(n.)
"He's such a gubby puppy."
"Don't take him seriously - he's just a gubby."