Spiders that bite and chew and leave bumps of poison all across his skin. Spiders explode in your face and they’re not the nice spiders - yes there are nice spiders and they follow him around and protect him, at least until they’re smushed - no the exploding eggs always have evil spiders. Even something that seemed so harmless, so enticing, would draw you in with whispers and promises of freedom (and he thinks he can hear those coming from the eggs but truly what is real and what isn’t in this endless hell) and then as soon as you close enough… No, Isaac knew by now that nothing could be trusted.
No rock, no chest, no lump in the carpet.