Strange slug

Strange slug

Observation - Strange slug - UK and Ireland. Description: I found this while I was weeding the veg patch, tucked under some old carpet. It looks like a slug but is firm to the touch and is a yellow colour - texture and colour unlike any 'normal' slug I have seen. Other slugs nearby look and feel 'normal' thoug

I found this while I was weeding the veg patch, tucked under some old carpet. It looks like a slug but is firm to the touch and is a yellow colour - texture and colour unlike any 'normal' slug I have seen. Other slugs nearby look and feel 'normal' though they are torpid in the cold. It is 13mm long but appears a bit 'hunched up'. Could it have been parasitised? Apologies for poor focus.