Reviving Tomatoes restore Kirby's Health completely when used, just like a Maxim Tomato. Reviving Tomatoes have a more impressive power, however; if Kirby has one of these items in storage when he is KO'd, it will automatically revive him to full health in a flash. If the pink puff defeats the boss without using his Reviving Tomato, it will transform into an ordinary Maxim Tomato.
A Reviving Tomato is a shiny gold tomato similar in shape to a Maxim Tomato. It has greenery growing out its top and its front is adorned with a star logo.
Found inside the Assist Star. It will automatically replenish all of your health meter if it's depleted.”