Lightly spray a gelatin mold or bundt-style mold with nonstick spray. Use a paper towel to gently spread the spray around the inside so there are no heavy puddles.
Add the warm water to a large mixing bowl. Sprinkle in the beef gelatin and whisk until dissolved.
Add the blueberry drink packet and whisk until fully combined. The mixture should look smooth with no dry gelatin clumps.
Add the nonfat Greek yogurt and whisk until the mixture is creamy and even. Make sure there are no yogurt streaks left.
Gently stir in the blueberries with a silicone spatula.
Pour the mixture into the prepared mold. Tap the mold gently on the counter to remove air bubbles.
Refrigerate until completely firm. This will need at least 4 hours, but overnight is best for the cleanest slices.
Once fully set, gently loosen the edges if needed. Turn the mold over onto a plate and release. Slice and enjoy cold.