Gold

Gold (Aka Coins) is the most common of the freemium currencies used to buy low tier items in the default shop, along with skins and wares from the merchant. Gained from Valuables Chests, the  Thief, and cadets, they appear as placeable items most of the time and thus are able to be merged into larger "piles." These piles of currency can be transformed to the actual currency via feeding them to the devourer.