In a medium microwave-safe bowl, add the caramels, half of the cream (reserve the remainder), and heat on high power to melt. It will probably take about 3 to 4 minutes total, but you must stop and stir the mixture every 30 seconds so you don't burn it. The first few times, stirring is almost futile but eventually the caramels soften enough to be stirred smooth. Take your time, don't overheat or heat too quickly, and keep stirring; it will come together. If the mixture seems thick and needs more cream, add the remaining amount. I used 1/4 cup total and have made the recipe with both Kraft brand caramels and Werther's Baking Caramels, but caramels vary and you may need less cream than I did. The caramel is runny and loose when it first comes together, but firms up quite a bit as it cools. Alternatively, you can melt caramels on the stove over low heat, using caution and stirring frequently.
In a medium microwave-safe bowl, add 8 ounces chocolate and heat to melt, about 1 minute on high power. Heat in 15-second increments until chocolate can be stirred smooth. I prefer working in smaller batches with chocolate and recommend doing the same and not heating all 16 ounces at once; melt additional chocolate as necessary.
Allow Turtles to firm up at room temp (will take many hours) or in the fridge or freezer (about 15 minutes) before serving. Turtles will keep airtight at room temperature for weeks, or in the fridge or freezer for many months.