Source was a wallpaper site called walldevil, and later I found a version that was mirror-imaged at a site called zastavki. Not sure how satisfied I am with this avatar so you may see more avatar changes.
The green creature is an alien species found in Metroid Zero Mission and Metroid Other M, and it's called a Baristute. I have no idea why it has a name that rolls off the tongue so well. The courtroom wig, however, is some stock art I found on the internet and added in GIMP, because a barrister might wear it.