Beaten with a shovel, a drill bit in his head, and clubbed to death

Question: A man named Tom goes to a party. Him and three guests go into a back room to play some games. A few hours later the four of them are discovered dead. One was beaten with a shovel, another had a drill bit in his head, and the other had been clubbed to death. Tom has no marks on his body.

How did he die?

Question: What do you call a mad elephant?

Question: What kind of mouse does not eat, drink or even walk?

Question: What fish only swims at night?

Question: Where do all the letters sleep?

Question: What tastes better than it smells?