Hide. Due to the dragon's small size, it can hide very easily amongst clothes or behind other creatures larger than it, gaining a +5 to stealth and a +2 to its AC. Amphibious. The dragon can breathe air and water. Coin Safety. The dragon will only move away from its coin for a short distance. Once the dragon has moved 30ft away from its treasure, it will become anxious and return to its coin.
Multiattack. The dragon makes 3 attacks, one with its bite and 2 with its claws. Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 6(2d4+5) piercing damage. Claw. Melee Weapon Attack +10 to hit, reach 5ft., one target. Hit: 4(1d4+2) piercing damage. Breath Weapon. (Recharge 4-6) The dragon uses its breath weapon. Fire Breath. The dragon exhales fire in a 15 foot cone. Each creature in that area must make a DC 17 Dexterity saving throw, taking 5 (1d10) fire damage on a failed save, or half as much damage on a successful one.
A tiny dragon that simply cuddles onto a random gold coin and never lets it go, you can take the coin but you must also take the dragon. You may spend the coin as well, but the dragon will go with it. Original concept by XaviarBlackrose on DnD Beyond.