Note: Only tested in blender 2.81, should work for newer versions as well. Pose the tongue by modifying the curve, you can twist a curve vertex by selecting it in edit mode and pressing ctrl+t, you can also modify the radius of a curve vertex by selecting it in edit mode and pressing alt+s. These settings can also be found in the Item->Transform panel.
scaling the tongue model is sort of weird since it uses an array modifier with a curve, but this is the process: 1. Select the start tongue piece, end tongue piece, main tongue piece and the curve. 2. Scale the objects. 3. Apply the scale with ctrl+A on the start tongue piece, end tongue piece, main tongue piece. DO NOT APPLY THE SCALE ON THE CURVE. 4. done 5. I have no idea why it's so janky to scale it, if anyone sees that I'm doing something wrong then please send me a message!