Released as part of Jagex's 'Scream of Fortune' promotion for the Halloween season of 2012, sugar skulls (won in batches of 5) activate one of these temporary effects upon consumption (like the toffee apple):

• The message "You feel the lasting effects of sugar" means your lifepoints have been healed by up to 500 - with a further 10 added per second for 10 seconds.
• The message "The sugar gives you a rush of energy" means your run energy has been restored back to 100%.
• The message "The sugar makes you feel more skilful" means all of your skills, with the exception of Prayer, Summoning, and Constitution, have been increased by 2 levels for 1 minute. However this will not stack with existing boosts such as those granted by Overloads.
• The message "The sugar was so nourishing you didn't need to eat it at all." means that the healing effect has been granted without the skull itself being eaten.

Sugar skulls cannot be dropped or traded, only destroyed. However they can be converted to 399 coins via High-Level Alchemy, 266 through Low-Level Alchemy, or 1,000 on the Squeal of Fortune's rewards menu. More must be won again in the same manner.