A gazelle is one of many antelope species in the genus Gazella... Gazelles are known as swift animals. - Wikipedia
Gazelle is a lightweight replacement for Ermine.
To run it:
fx set workstation_eng_paused.BOARD \
--with //src/experiences/session_shells/{ermine,gazelle} \
'--args=application_shell="gazelle"'
fx build
ffx session launch fuchsia-pkg://fuchsia.com/workstation_routing#meta/workstation_routing.cm