Isn't this covered under fair use via parody? Does Tumblr not have a counter-claim system in place?
From Tumblr
Submitting a DMCA Counter-Notification:
If you believe you are the wrongful subject of a DMCA notification, you may file a counter-notification with Tumblr by providing the following information to the Designated Agent at the address below:
The specific URLs of material that Tumblr has removed or to which Tumblr has disabled access.
Your name, address, telephone number, and email address.
A statement that you consent to the jurisdiction of Federal District Court for the judicial district in which your address is located (or the federal district courts located in New York County, New York if your address is outside of the United States), and that you will accept service of process from the person who provided the original DMCA notification or an agent of such person.
The following statement: "I swear, under penalty of perjury, that I have a good faith belief that the material was removed or disabled as a result of a mistake or misidentification of the material to be removed or disabled."
Your signature.
Upon receipt of a valid counter-notification, Tumblr will forward it to Notifying Party who submitted the original DMCA notification. The original Notifying Party (or the copyright holder he or she represents) will then have ten (10) days to notify us that he or she has filed legal action relating to the allegedly infringing material. If Tumblr does not receive any such notification within ten (10) days, we may restore the material to the Services.
But in practice what it tends to result in is Tumblr ignoring your counter-notification and leaving you hanging despite repeated emails.