Derived mine from a render I found by using good 'ole Google.
I see no reason whatsoever to credit render artists unless they speak up and identify themselves...oftentimes you just can't know who to properly credit, and the ones who insert little signature bars into their renders are not being considerate to the people who will use it to create nicer images. That being said, most renders are copypasta'd and processed, and are not 100% original hand-drawn art.
So yeah, scaled render to create image...I didn't feel like putting a background behind it and ruining a perfectly good standalone image. Note that when I use renders I never claim to have made the image itself, just performed the required processing tasks to incorporate it into my theme.
My biggest beef with artists online of any kind is against artists who B&M when you use their image somewhere else online...even if you don't claim that you drew the image yourself. If you didn't want it posted, reposted, edited, and otherwise copied...then why the heck did you put it online? This goes the same for the crotchety spriters I see here on PC. If some n00b uses your sprites, don't B&M about it unless he actively says that HE sprited them.