Killing them Twice (Encounter idea)
Here's one for you DM's that want a fight that happens right after a fight! The players are fighting a very old warlock in battle. After awhile of fighting the warlock will start having a heart attack & will send out their most powerful spells in desperation to beat the party. If the party survives that the warlock will have a heart attack & then go still on the ground. If any of the players go to check on the warlock they will find that the warlock has no pulse. Once the party do what all parties do (loot the dead) & begin to leave they will hear a very eldritch sound come from behind them. After they turn around (& or procced to try & leave the room) they will hear maniacal laughter that appears to be coming from the corpse. After about 7 seconds a ghost will rise from the body & then engage the party once again.