There's now a Witcher 3 mod that lets you ride around on a full-size dragon Skyrim-style, just in case you don't fancy a piggyback from an alchemist
In possibly the most visually interesting case of someone combining another thing I like with The Witcher 3 via a mod since someone slapped Kazuma Kiryu's back tat on big Gerry, there's now one that'll let you ride on a dragon a bit like Skyrim's Dragonborn can after visiting Solstheim.