Term for derogatory suffix used with city names?

When speaking of a city in negative terms one might attach a prefix/suffix to the city name. This nickname is a portmanteau that implies a derogatory tone. Most often this will be a negative term but can also be another geographic name. Is there a specialized term for this use? I’m particularly interested in a term for the geographic modifier case.

Examples:

• I live in Spokcompton. (Spokane + Compton)
• He lives in Fayettnam. (Fayetteville + Vietnam)
• Hollyweird
• Fithadelphia