Mirrored from Sudopedia, the Free Sudoku Reference Guide
These are the possible configurations:
The irregular patterns make it possible to find larger Franken Fish than for fish types limited to rows and columns.
Although a "Franken" X-Wing is technically possible, but this degenerates into some other elementary single-digit technique, such as Claiming. Therefore, only Franken Fish of size N at least 3 is discussed.
Originally, the box constraints in a Franken Fish were seen as possible fins, but it turned out that the boxes themselves belonged to the pattern.
All other fish with mixed constraint types are Mutant Fish.