What animal is this?

I think this is a bacon beetle larva, of which there are several:

https://www.google.de/search?sca_esv=593706337

Which exactly from this family (such as carpet, Berlin, wool-flower beetles, etc.) remains quite the same, because all are among the material pests in the household.

The bugs fly to the window, they want to get out, but their larvae eat textiles, wool fabrics, mattresses, upholstery, feathers, carpets and some more – making them unusable for us.

Please control everything exactly:

• in bed, bed frame, mattress, pillows and blankets
• in the wardrobe, also in the edges, corners and ridges
• on garments, furs and other woolen fabrics
• Dry food for pets
• dry food, such as cookies, dry meat…

Wash infested textiles at least 60° or freeze for a few days, dispose of infested food outside the house.

Soils suck very well, here also the edges and strips do not forget, because these larvae are masters in hiding.

https://dgk.de/meldungen/speckkaefer-haarige-gesellen-in-der-kuechenschublade.html

More tips here:

https://www.dfnt.com/ratgeber/speckkaefer-bekaempfen/