How to make a slime block in minecraft?

Slime blocks are not pulled by a non-sticky piston, nor are they moved if an adjacent (non-slime) block is moved by a piston. The maximum of 12 blocks moved by a piston still applies. For example, a 2×2×3 of slime blocks may be pushed or pulled by a sticky piston as long as no other movable blocks are adjacent to it. read more

The Slime Block is a block implemented to the game in snapshot 14w02b. It can be crafted by putting nine slimeballs in a crafting table. It is used to bounce Entities, making it good for map makers. read more

To make a slime block, place 9 slimeballs in the 3x3 crafting grid. When making a slime block, it is important that the slimeballs are placed in the exact pattern as the image below. There should be 3 slimeballs in the first row, 3 slimeballs in the second row, and 3 slimeballs in the third row. read more