Miku Hastune Pixel Art by Vixie99 on Source Engine
In the download you will have all the files used to make the sprays and render. Also you have various type of sprays. The first one is mikupixel.vtf/vmf, this is the "normal", it has all the body of the pixel art in 512x512 resolution.
Some games doesnt support that, for that you have the second that its mikupixelR.vtf/vmf. This is the same spray but in 256x256, so you can use it on your game. I think CSS doesnt support 512x512, so try it. I want to mention that it has lower resolution and it's the ugliest one.
The last one is the mikuPixelExpanded and mikuPixelExpandedR.vtf/vmf, there are the same spray. There are in 256x256 and its the expanded one, it has only the upper body. Why there are two files of the same? Because i thinked that the first one was on 512x512, my bad.
Also! You have all the spray images on this post. The screenshots were taked on different maps so you can check the diference.
Last but not least this sprays work (or i think they do) in other Source type games. Just check it, you have a .txt for "how to install them" in the .zip