Ha, same here. I buy a thermometer and suddenly I’m being shown ads for 100 other thermometers. Amazon’s AI isn’t going to be overthrowing humanity anytime soon. 
Update: 2019-02-09
Hi everyone, I think I just found a way to avoid these annoyances with the Google Ads. Here’s a brief explanation:
The Google Ads settings allow me to choose between showing just text ads or showing image ads, and I’ve always strictly stuck to only text ads so as to avoid risqué images and flashing, blinking, bouncy annoyances for our users. But what I didn’t know is that even with “text” ads, they apparently added during recent years some “enhancements”, which include images and flashing annoyances. I don’t understand how they get away with still calling that a “text” advertisement, but it is what it is. There’s even an option to allow ads to expand beyond their normal size, which is apparently what Raccoon was seeing in the OP. Of course they added these “enhancements” and enabled them by default in a very obscure part of the settings panel. 
But the good news is that I believe I just now disabled all the “enhancements” so that it will now show strictly text ads, as I always intended. Please let me know if anything changes for you now (it might take an hour or so for the new settings to take effect).
Thanks again to everyone who reported this, and my apologies for the unintended annoyances up until now! 
