Squidward House from Spongebob Squarepants show to use as fish tank decoration/ fish hideout.
I divided this model into different parts to minimize supports. I've added a small tolerance in the holes and tabs that connect each part, but you may need to adjust the horizontal expansion in your printer settings or glue the pieces together.
The skirt in the bottom of the model is ment to burry under your fish tank soil to anchor it to the bottom.
Materials: Pick materials that are safe for both your fish and plants. It's usually recommended to use ABS or specific food-safe PLA, and it's often advised to coat the print in a safe epoxy to seal it.