Baby nightmares

Over the past week my LO has woken on a couple of nights with a loud high pitch scream, terrified & crying almost as if he has had a nightmare

He usually just rolls over and smiles at me as if to say “what the hell am I doing in my cot rather than your bed” or he will tap my arm ( his cot in next to my bed) or just googoo gaagaa at me

It’s very unusual for him as he is not really a crying baby

He is looked after by me 24/7

He is 10 months old

Do babies have nightmares?

How can I help this