Answer to the Parasite Case of the Week 666: Echinococcus sp. degenerating protoscolex (immature scolex) and free hooklets. We can't say which species of Echinococcus is present from the image alone, but it is most likely to be E. granulosus, as this is the most common species to infect humans, and it commonly forms a liver cyst that is amenable to aspiration.
This is a beautiful example of rostellar hooklets in a protoscolex.
Here are some other great examples of Echinococcus sp. protoscoleces and hooklets in aspirate fluide from previous posts:
Case of the Week 514: