Mousetrap Door (CR 3)
At the end of the hall is a wooden door with a metal frame.
Type: mechanical; Perception DC 22; Disable Device 22
Trigger touch; Reset None
When the door is opened, the metal frame snaps down on the character like a mousetrap. Mousetrap(DC 19 Reflex Save or take 2d6 damage and become pinned. CMB vs. 22 CMD to Escape)
Even though this might not kill anyone, the visual imagery of this trap going off is worth its weight in gold. If you really want to make this one memorable, have this be located at an entrance to a giant's lair with an oversized cat. Perhaps that cat can even enter the room through a large pet door. If your PC is soloing it, have some dire rats appear as soon as he is caught.