6x6 cats and dogs puzzles
These Pawmoku 6x6 library puzzles have 36 tiles, with 6 tiles in every row and column. A finished line needs 3 cats and 3 dogs, without three matching neighbours. The 25 published so far start with 6 to 16 animals and take 20 to 30 steps to finish.
Solving 6x6 boards
Three of each animal belong in every line. Scan for pairs and gaps first, then count lines that already contain several starting animals.