Single Collateral DAI is a decentralized stablecoin that has collateral to back its value and an interest rate mechanism to stabilize its price. It is designed to be a digital currency with a stable value, that is pegged to the US dollar. (1 SAI=$1) MakerDAO is the decentralized autonomous organization that manages DAI and works to combat its price volatility. MakerDAO hopes to enable more decentralized applications by providing a stable digital currency whose value will not be susceptible to drastic fluctuations. The Maker platform itself, is powered by the MKR token, which is not a stablecoin, and has a volatile price because of its role on the Maker platform. In November of 2019 MakerDAO launched the Multi-Collateral Dai (MCD), which will eventually replace the existing Single-Collateral Dai, and will enable the company to offer a wider range of DeFi services.

PAX Gold is stablecoin backed by gold. Each PAX Gold token is backed by one troy ounce (t oz) of a 400 oz London Good Delivery gold bar that is stored in a physical vault. PAXG holders own the underlying physical gold that is held in custody by the Paxos Trust Company, which is a regulated financial institution. Paxos specializes in providing custody and infrastructure solutions that enable movement between physical and digital assets.

Dignity is a stablecoin pegged to gold, that was developed by the company Cryptobontix. Each DIG token is pegged to the worth of 0.02445 grams of gold, which was worth exactly $1.00 at the time of the Dignity whitepaper.
Cryptobontix's portfolio of stablecoins are based on a partnership with bullion suppliers. Each individual token acts as a security on a 15-year convertible mortgage. The DIG token is pegged to the value of gold. Every year, 1/15th of the tokens can be redeemed for gold valued at around $1.00.
Cryptobontix does not actually own all of the physical gold. The company plans on spending its profits on acquiring the actual bullion that token holders will have the option of converting.