When i was like 5 i had guite often a dream about a lake, wich was on my way home and i would always end up playing on the water, then a black and white monster would appear and eventually catch me no matter how hard ran, fell down and crawled on the knee deep water. *shrug*
Nowdays a recurring theme is that i beat endlessly some fantasy thingy(dwarf, golem, werewolf, ivisible man). They are stronger but not as fast or good fighters as i am.
Not scary, more like frustrating.
Holy shit, i just realised that i can just describe them perfectly as boss fights that i wake up from before they end.
Thankfully most of my dreams are pleasant and sometimes even under my control.
EDIT: Forgot to mention that i handled my nightmare problem around 8 years old by half realising that its a nightmare and physically opening my eye-lids with my hands, and when i realised thet i could do that i started to have less and less nightmares.