The game puts slimes into a main - domesticated - focus, so I'm not surprised some slime ideas from SK would be recycled.
*Fire Slimes seem to share inspiration with
Oilers, only they're self-lighting and don't drop oil as a hazard.
*The
Slimepedia icon of the Tabby Slime bring to mind the passive forms of
Kats.
(
NPC Kat with the face for reference)
In general I would say it's not unusual to get inspiration from other works, including if one of those works are your own. The game has a fair few references to the game if you look (
Royal Jelly and
Royal Jelly), but is still its own thing. I don't see an issue myself, in part because I love SK. Even if I haven't been on it recently.