Nanosmilus was bobcat-sized a North American sabretoothed nimravid (a type of carnivore very closely related to true cats). The name "nanosmilus" means "little carving knife", because it's one of the smallest sabertooths known. All I could find were pictures of the skull and there isn't much info about it online, so I had to guess a lot from looking at its close relative, the leopard-sized Eusmilus - take this reconstruction with a very large grain of salt. I usually like dramatic lighting situations, but I went with a cool, overcast day and no strong light source for this one, and gave it a camouflage pattern. It ended up looking like my one cat, Minnie.
The background was adapted from stock by tamaraR-stock on DeviantArt.