Horsey Two-Horse was the beloved steed of Baston. He first appears in Classic Six Behavior (2.02) as Baston rides up to rescue Freezo (and incidentally Philge) from an angry mob. Together they escape into the woods.
Baston is forced to leave Horsey Two-Horse when Kareena leads the group into a network of narrow cairns. After a teary goodbye, Baston slaps Horsey Two-Horse's rump and sends him running down the road.
Unfortunately Freezo had recently learned that he gains 4 Temporary Hit Points every time he kills a creature. Seized by bloodlust and the fear of his own mortality, Freezo shoots Horsey Two-Horse with his newly-upgraded Eldritch Blast and kills him instantly.