MOUNTED GANDALF - THE WHITE & THE GRAY. ARMIES OF MIDDLE EARTH
Gandalf the White is pretty much as he originally came - just stuck on a different base (which is 90mm in diameter).
Gandalf the Gray is made up from the GtG foot figure and Eomer's horse etc...
Both from Play Along's now defunct Armies of Middle Earth range of pre-painted Lord of the Rings figures with typical human height being around 65mm.
An ideal and cheap source of large scale skirmish gaming figures if you search eBay.
Here's some links to other parts of this site if you fancy a similar hobby project yourself.