Estimated difficulty 3.0/10
Master target time 00:08
Expert target time 00:45
Answer Not yet present
Solution Not yet present

Special Puzzle 10: A Regular 5×5 Fillomino!
Fillomino

Yes, it’s a regular Fillomino. A 5×5 Fillomino. So why do I post it as a special puzzle? Because it’s 5×5.

This is one of the most nontrivial 5×5 Fillomino I have ever seen. It also features an amazing (anti)symmetry. If I don’t have this Fillomino:

…what are those badly drawn “headgears” doing there? And what is that lower-right thing?

…that features 492 and 471 (which, if you can see, is the background of my hand-made avatar:

I need to get a higher resolution avatar.

… ), I would have used it everywhere. (Luckily it needs the two empty spaces at the lower-right, so if I need a pure Fillomino, I prefer the antisymmetric one above.)

Heh. What am I doing?