Ethels amusing bubble hat makes an appearance in the episode, “Tennessee Ernie Hangs On” (S3, 5/10/54)
It is by Mattel called Bubble-O-Bill. There are a couple of them in original box on eBay this week:  https://www.ebay.com/sch/Other-Vintage-Antique-Toys/30/i.html?_sop=15&_from=R40&_nkw=bubble+hat+mattel