This is a paid asset, but now you can download Mosquitos pack Free.
Detail this asset from Unity Store: Original Link
Mosquitos pack v1.0
Here are two mosquitos and each one of them have two different textures. Also package include 15 animations.
Polygon counts:
Mosquito 1 – 2661
Mosquito 2 – 2492
Animations list:
Hit from four sides
Two death
Three kind of stings
Two kind of fly
Flying end and start
Run
Idle