There are a number of different causes of Super Scary Shocks encountered in the game.
List of Super Scary Shocks
In the second scene of the Grabbed By the Ghoulies, the Trophy Room, there are several trophy heads of large beasts and other cameo characters. During Cooper's short first-person journey through the room, trophy heads will randomly come alive and scream at Cooper, initiating a Super Scary Shock. The main purpose of this room is purely to act as tutorial, as he cannot faint no matter what.
The Ancient Mummy
At the end of the first-person entrance in the Relic Store, an Ancient Mummy will spawn from a sarcophagus, startling Cooper. This is the only time an Ancient Mummy will cause a Super Scary Shock.
After being transformed in a Ghouly, Amber will look back at Cooper and give him a Super Scary Shock.
Medusas can always startle Cooper just as long as if he stumbles into her green light Dropper. Otherwise, Medusa will attack with her 'hair'.
During Cooper's visits to the Embassy Ballroom the Dropper Shocker will drop from the ceiling and scare Cooper whenever he either enters or re-enters the door to the Lower Corridors. It reappears later in the Stables.
Hand in the Ground
After leaving the Workshop and entering the Lower Corridors, when Cooper is about to leave the room, a giant hand will come out of the ground and grab Cooper thus scaring him. If Cooper survives, the hand will put him down allowing him to pass. It also appears in the Greenhouse (both visits), the Farmyard (Second visit) and the Grand Hallway (Fourth visit) of Chapter 3. Its last appearance is in the Pantry and Lower Corridors of Chapter 5.
In the Music Room, just as Cooper approaches the Door to the Walled Garden a large creature will jump out, shattering the door and scaring Cooper. If Cooper survives, the creature will retreat back into the door allowing Cooper to enter. They also appear on Cellar (Second visit) and reappear in the Attic. The guard dog makes its final appearance in the Pantry of Chapter 5.
After the first battle with the Warlock in the Housekeeping Store, a large one-eyed octopus creature will spring out of the washing machine near the door. If Cooper manages to survive, it will quickly retreat back in to the washing machine. This creature also appears in the Attic and the second visit to the Laundry in Chapter 5.