Previous Versions can be found here.
Rudolph, or Rudy for short, was added in Mid-Season 45 (Beta 45.1).
Much like his daughter Noelle, Rudy is an Epic monster with an ability to very effectively heal up its owner. In his case being a 6 HP Magic for 5G, while also supporting a 5/4 body.
To compensate for this powerful combination, the Magic only works if you lack any non-Generated spells in your deck. This makes Rudy work very well combined with Bookshelf, which has the same requirements (and was added in the same update).