Quote from PigAteMyPie
Today i'm going to show you how to make a monster spawner on creative mode.
First, you will need these things: A few monster eggs, a dispenser and a redstone power source. (redstone torches, lever, pressure plate, ect.)
Second, how to put it together. 1: place the dispenser down. 2: put the egg inside the dispenser. 3: power the dispenser with the power source, and you have made a monster spawner.
HINT: you could try placing multiple eggs in the dispenser to make it work like the real ones!