Have you heard about the Hidden Eloise vs Paperchase case? Well, if you haven’t, take a look at this link. It’s all about people stealing artist’s drawings or illustrations on internet. I hate when it happens, I get angry easily, and it’s a very uncomfortable situation, because I really fight for my rights – the only thing I have!
I share my doodles, artworks… I don’t put watermark, etc. So I trust you!
Answering the big question, “May I use your drawings?”: well… you can save them and use as wallpaper or show to your mom, post in your blog/site for divulgation… But, please, never rename the files (filename_tatimaia), nor even claim yourself the author of them! Oh, and you can’t use them in your design, change them, retrace them, etc, etc, etc.
People think that all images they find on Google are free for use. That’s not the truth! Always ask the author’s permission (or buy a custom artwork – it’s much better have something specially made for you… by the way… I do commissions too! XD).
When you look for images, search on Stock Images websites. There’re free images, and also paid ones… And those are very cheap, like $1 or $10.
I hope I am helping. If you have more doubts (or discovered someone using my art), don’t hesitate to comment or message me. 
Edit: I missed the SketchCrawl yesterday. So, at least I am posting some doodles. The guy singing Fly Me To The Moon is my husband, Fernando.
