8x16 — The Walking Dead

: During his final fistfight with Negan, Rick smashes the glass and uses a sharp shard to slice Negan's throat.

It delivers physical retribution to Negan for his past atrocities. The Walking Dead 8x16

The shard of glass is a highly intentional narrative tool representing the episode's core theme: : During his final fistfight with Negan, Rick