On mobile, the ads I see are almost exclusively fake virus warnings, "clean your phone" and other crap like that. Complete with flashing yellow and red images.
Are those Google Ads though? Google is indeed a dominant player in the advertising market, but they're not the only one. You could be seeing ads from a different ad network.
All of those things you described (fake virus warnings, "clean your phone", flashing yellow and red images) are against Google's policies for AdWords. See:
