Sponge

Sponge is an alien-robot friend in Cave Den, who is made out of wool and ore blocks. He is built on the dance floor, and has a beacon running right through his brain.

Changes
In episode 56, "Upgrade," Sponge is remade, and his spongy body is taken away and several colors of wool are laid down to replace is sponginess.

Beacon
His beacon is maximum size and made of diamond blocks. It goes right through Sponge's head, is stained yellow and goes right up into the sky, right above Cave Den. Sqaishey is the only person who has been there in the series.