- Type letter ‘c’ using the text tool, as you’ve already done
- Create a new layer from text
- Duplicate layer
- Transform - flip horizontally
- Merge two layers
It’s a basic GIMP knowledge, really. Don’t forget to add an alpha channel to your layer after step 2, otherwise it won’t work.



And the results are heeeeeeeeere!
Spoiler:
dpkgis the winner, but popular vote goes toperl-base.libc6is at the distant 28-th place, which makes no sense to me.