Animate a 3D Jack O' Lantern in GIMP (updated)

This tutorial describes how to create an animated GIF in the free alternative to photoshop: GIMP.
Check out https://www.instructables.com/id/Model-a-3D-Jack-O-Lantern-in-CREO/ for instructions how to design a 3D-Jack-O-Lantern in CREO.

Step 1:

1. Open the rendered image in Gimp.

Step 2:

2.  Select the bottom half of the image, create a new empty layer and go to Filters --> Render --> Clouds --> Fog, use a grayish color.

Step 3:

3. Duplicate the new layer for denser fog.

Step 4:

4. Create a new empty layer and go to Filters  Render  Clouds  solid noise. Bring down the layer opacity until the pumpkin is visible again.

Step 5:

5. Go back to the first layer and select the holes in the pumpkin with the fuzzy select tool. Use `add to current selection mode` to select multiple holes. Copy this selection to a new layer and fill with a light-yellow color.

Step 6:

6. Add another empty layer and use the paintbrush tool to add light effect. Now you have to group the layers into two groups: one pumpkin without light emitting and one pumpkin with light emitting. Export both to a jpeg file.

Step 7:

7. Create a new image, paste the two jpeg’s and duplicate the layer without light emitting a number of times, as every layer will become an animation frame. Finally Export to GIF. Make sure to select “as animation”.