After capturing Daryl, Michonne, Carol, and Yumiko, Alpha took Daryl out over a valley to show her that she is not making empty threats. She has a massive horde of walkers and Whisperers ready to defend or attack as she sees fits. After showing Daryl how massive her army is, she sent him off to see a marker of her territory, vaguely promising that he will know what she is talking about. Daryl and his group saw exactly what she was talking about on the northern border of the Whisperer land.

Alpha marked her group’s territory with a set of 10 pikes, each of which had the head of known character placed on top of it.

The 10 characters Alpha and the Whisperers killed for this pike sequence were Henry, Tara, Enid, Ozzy, DJ, Addy, Tammy, Frankie, Alec, and Rodney.

This is a major change from the pages of The Walking Dead comics. In the books, the biggest names on the pikes were Rosita and Ezekiel. Furthermore, Rosita was pregnant at the time of her death in the books. However, the show elected to change the story from the source material in favor of preserving their lives.