Food in Monster Legends.
Food is an item used to feed Monsters to increase their level, so they can become stronger and generate Gold faster. Food is also used instead of Gold to upgrade some buildings, like upgrading Habitats to level four or seven.
Food is mainly grown on Farms, but can also be earned by other means, like completing a level on the Campaign Map, collecting your Daily Bonus, or stealing Food from other players in the Monster Arena.
Like Gold, you can purchase Food using Gems, which is purchased using real life currency.