Yeah this is a really sucky part of parenting cos we know what they are dreaming about is pure imagination, but for them it is very real, and seriously tough to deal with in the middle of the night when all you want to do is go back to sleep.
Brandon dreamt about vampires and Liam has giants.
With Brandon I got some coloured sand and told him it was fairy dust and there to protect him from all things scary, I also got him a pretty swizzle stick to use as a wand and if he woke up in the night he could wave it around to chase away the scaries.
With Liam I found a spray called "Monster Vanishing Spray" which has all sorts of essential oils like camamile, lavender etc, so smells really nice and giants don't like things that smell nice, so now they won't go in his room.
Then for both of them I recently read a book called "The Kiss Soldier" where the grandfather would kiss his finger and press it agaiinst the child's head board and a little soldier appeared whenever the LO woke up at night, so using that one as well.
And for really bad nights, I have glow sticks for them, which also seem to help, even tho they both have night lights on.
But also during the day I get them to tell me about the dreams and then we make up a game with it, or make new endings etc which makes the vampires and giants more friendly.