Just like Justine points out, I was about to suggest fun/play time in his bed during awake time. Like peekaboo, reading books, playing hide/n seek stuffed animals under the sheets, playing putting stuffed animals "to bed" etc.
Then, you can try to sneak into his room 10-15 mins prior his usual wakings (during night time and nap time) and observe what's going on prior his waking (is he tangled in the sheets, or with a foot stuck on the crib bars, is he wide awake or crying in his sleep) to solve the mistery. That can also help him see you right away when he wakes and be more calmed with your presence and relax about it. Remeber all the time to him that it's ok, it's just a dream, reassure him and cuddle him as much as he wants/needs and he should be back on track within a couple of days. I can't remember where i read it but with this "love" treatment, night terrors tend to vanish within a week or so.
Good luck, this must be really stressing for you but remember that as they grow into toddlerhood, dreams tend to be more vivid cause they're able to remember and understand much more, and are starting to make connections between cause and effect. Try to turn this on your side by making it fun and play lots of cause and effect games (like turning playdoh into an animal and then again into a ball, etc.). Something I do a lot with lo is play with stuffed animals things i usually do with him, like Monkey doesn't want to eat his veggies, should we give him a chocolate... to my surprise he often says No and puts monkey in the crib... they understand much more than we can take on account, so play along that and you might be surprised and he might tell you what's scaring him (on a funny note, ds told me today that nanny had broken a cup and hidden it in the wastebasket LOL... i went through it and found the broken cup) hehe it pays off to research their feelings and fears.
Good luck again, I hope this phase ends soon!
