Reddit mentions of Energizer Hard Case Professional 3-LED Puck Light (Batteries Included)

It is just a standard jar I picked out at hobby lobby that was a hard edged cylinder. Lucky for you I posted a write up in /r/metroid. (I probably should have sold them as kits!)

PARTS LIST:

1. It starts with making a baby metroid perler. You can find the original sprite at the spriters-resource Pick your favorite!
   
   
2. Pick out the colors you require. Here is a handy chart. You can get perler beads at most hobby stores (Joanns, Hobby Lobby, Michaels)
   
   
3. Acquire pegboard. here's an example It comes with parchment paper. follow the directions for melting with standard clothing iron (Steam setting should be off)
   
   
4. Pick out jar. Choose cylinder with hard edges.
   
   
5. Acquire Water beads here. Note that you only need 1tsp for 16-20oz. They expand 300x their size.
   
   
6. Fill jar 1/3 full of water beads and place baby metroid centered in and level in the jar.
   
   
7. Fill remaining portion of jar with water beads so the sprite stays still. Now fill the jar slowly with bottled water so all voids are filled. Go ahead and give it a couple taps / shakes for the bubbles to be released.
   
   
8. Pick up base light. I really recommend this one. It has a rubberized sleeve that has good tacticity so the jar won't slip off.
   
   
9. ENJOY!