Likely bed bug (possibly crushed or engorged)

Hides in mattress seams, bed frames, furniture, and other cracks near sleeping areas.

Feeds on blood, usually from humans, and typically feeds at night.

Flat, oval, wingless insects that hide by day; infestations spread through luggage, clothing, and used furniture.

Bites can cause itchy skin reactions and infestations are difficult to eliminate; bed bugs are not known to transmit human diseases. The photo alone cannot confirm identification.