2yo dreaming? Waking in night again

[Newmum26]

My DS is 2 years a 3 months old and has always since 3 weeks old slept like an absolute dream. Apart from teething and illness which obviously disrupts sleep he has always gone to bed awake, we've said night night and he self settles and puts himself to sleep. Up until a month or so ago we would put him to bed at 7pm and wouldn't hear a peep from him until he woke at 7.30am ish.
Recently nothing has changed routine wise, but he goes to bed and cries out and shouts for me during the night 2/3 times usually after 3am ish. Sometimes he's sat up and eyes open awake but others he's still asleep just stirring and mumbling in his sleep.
He is a VERY mentally and physically active little boy, the HV came to do his review and was blown away but his vocabulary, it's like having a conversation with a 6 year old 😂 His brain is always busy, he is so keen to learn and is always asking questions.
Is it common at this age for them to have night wakings again? My HV said is is because he is so mentally busy his mind is still busy when he's asleep.
He even woke the other morning after crying out for me in the night and seemed upset, he said 'Mummy are there snakes in my bed?' 🤷🏻‍♀️🤦🏻‍♀️ His imagination has really taken off lately too.
I didn't even realise they got dreams at this age?! Anyone else have any similar experiences?
Thanks ☺️

Anyone? Noticing more and more on Mumsnet that you don't get many of any replies on a post, people seem to read and run 😟

We are having similar with my very nearly two year old dd. However she is no where near as vocal as your ds so cannot articulate what is wrong. She no longer wants to fall asleep on her own, and often wakes up in the night in hysterics. I think it may be the two year sleep regression, perhaps combined with some quite big changes at home; I am pregnant and she is aware of new baby coming, going up to next room at nursery and going for a 4th day a week, moved her into a new room (to try and iron out any issues ahead of baby needing the smaller room). She already has most of the traditional solutions at this age; bunny comforter, nightlight, good bedtime routine, so think we will just have to ride it out.

I can't help but I do remember coming into my parents' room for "snakes in my bed" for YEARS so it's clearly a thing. Think it was the folds in the duvet. Does he have a night light?