Can I put an 8 oz cream tube in a bag I'm going to check when flying?

you can put it in your checked luggage but not in your carry on

Yes. There is no size restriction on liquids in checked luggage. Just know that the changes in pressure can cause things to leak, so I would put it in a ziplock bag so that if it does, it does not ruin the rest of the contents of your luggage.

You may place this item into your checked baggage and any other such item that contains a liquid, gel, or aerosol whether it complies with the restriction or not. (There is no size restriction for checked baggage, only for items brought as carry-on. Please see link for more details.)

https://www.tsa.gov/travel/security-screening/liquids-rule

No the maximum you can have in one container is 3.4 ounces. Sorry

just avoid it. Its better

Just don't take it. Avoid the hassel

As long as its not a 9 oz cream tube or they will detain you