Viscous slime

Description
The Sun Warriors created another form of protection from intruders. If intruders try to steal their Sunstone located in the statue room a thick, viscous slime oozes out of the floor, trapping the potential thief. The slime is like glue. One it's on you, it's impossible to unstick yourself. In "The Firebending Masters when Aang and Zuko remove the Golden Sunstone from its pedestal, they activate a trap which closes the door of the room and fills it with the slime. Both of them remain stuck in it until the nightfall, when they are found by the Sun Warrior Chief, and subsequently released.