This is a really cool idea it is possible to do in survival but it would be really hard. I did it in creative for this instructable. Hope you enjoy.
Step 1: What You Need
What you need for the size I made is
78 Redstone lamps
78 wooden of stone pressure plates
(in creative) 1 spawn egg for the creature you picked. I picked silverfish you can also do chickens ocelots or pigs.
Step 2: First You.....
Place the pressure plates in a rectangle that is 8x10 you should no longer have any pressure plates left. Now place the Redstone lamps on top of the pressure plates.
Now put a edge around it in any block you choose. I picked quarts because I like how it looks.
Step 4: The Blinking Lights
How I made the lights blink was I then broke 1 of the Redstone lamps and started to spawn a bunch of silverfish in there then replaced the lamp. The lamps should now blink randomly.