Curious Expedition 2

Hyenas are usually found in the following circumstances:

• As an enemy roaming the map (2-6 Hyenas, can be found on most map types, not a guaranteed spawn though)

• As part of the the Beastmaster enemy's party (Can be 2 Hyenas but could be a different beast instead, not guaranteed)

• As part of a roaming villager event where they are attacked by Hyenas (2-6 Hyenas)

• The village quest to kill Snarfrattle the Hyena (2-4 Hyenas plus Snarfrattle, I'm unsure if they count)

If you find Hyenas roaming the map you could save scum this by manually saving and then dashboarding after killing them (but before you return to the map), but it's likely you'll unlock this during the multiple runs of the game simply by making a point to attack Hyenas or Beastmasters when you see them.