*Unearthed Arcana* (UA) 1e page 15 shows Cavaliers can handle and ride other mounts. And the Paladin gains the Cavalier abilities. > "4th level a female elven cavalier (and only a female elf) can ride a unicorn as a steed. > At 7th level the cavalier can handle and ride a pegasus as a steed. > At 9th level, the cavalier can handle and rige a hippogriff as a > steed. At 11th level, the cavalier can handle and ride a griffon or > a similar creature (DM's judgement) as a steed."