Is there a term for words like *Snowmageddon*, *Nipplegate* and even *cheeseburger*?

I know they're portmanteaus (or portmanteaux), but they seem to belong to a special class of portmanteau.

In the title examples, *Armageddon*, *Watergate* and *hamburger* seem to be the "mother" terms respectively (more so than *snow*, *nipple*, and *cheese*), and the derived terms *Snowmageddon*, *Nipplegate* and *cheeseburger* seem to be child terms in the sense that each *clearly* alludes to its mother term and could conceivably have sibling terms like *Floodmageddon*, *Lewinskygate*, and *chiliburger*.

Actually, the more I thought about examples of this phenomenon, the more I came up with examples that fit the description but weren't strictly portmanteaus. One might be "Rat Pack", which gets referenced by "Brat Pack" and "Frat Pack". Idk, maybe I'm getting too inclusive.

Is anyone familiar with a term for this or has seen a list of them? I love lists.