Obviously, this contains SPOILERS.  This lists how many cats can spawn in an area (only one will spawn per day) and what conditions they spawn under.



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6 cats in the forest (no conditions)
4 cats in the forest (spring)
2 cats in the forest (Sundays)
6 cats in Mountain (no conditions)
4 cats in Mountain (fall)
2 cats in Mountain (Thursdays)
6 cats in Backwoods (no conditions)
4 cats in Backwoods (summer)
2 cats in Backwoods (Fridays)
6 cats in Secret Woods (no conditions)
4 cats in Secret Woods (winter)
2 cats in Secret Woods (Tuesdays)
1 cat in Bathhouse Pool (50% chance)
2 cats in Witch's Swamp (75% chance)
6 cats on Beach (no conditions)
2 cats in Bug Lair (50% chance)
3 cats in Sewer (75% chance)
1 cat in Saloon (50% chance on Fridays)
10 cats in Town (no conditions)
1 cat in Abigail's room (75% chance)
1 cat in Sebastian's room (75% chance)
2 cats in the museum (50% chance)
5 cats at the railroad (no conditions)
2 cats at the railroad (Wednesdays)
2 cats at the bus stop (50% chance)
6 cats in the desert (no conditions)
4 cats in the desert (fall)
2 cats in the wizard's tower (50% chance)
1 cat at the Spirit's Eve festival