A further search coughed up this picture of the wizard from Dragonriders of the Styx in full regalia, including his odd little metallic "crystal ball" (with a handle on the bottom). Apparently there was also a variant of this figure, done in black with grey accents, that was e-e-e-vill, of course.
Perhaps the oldest wizard action figure I have is the Gandalf that Knickerbocker put out as merchandising for the Ralph Bakshi version of The Lord of the Rings, back in the late '70's. We got the whole line-up (except for Sam, which we never found); if we had been more foresighted we would have bought extras and kept them mint-in-box as investments, as even loose figures of this line are commanding huge prices for old pieces of plastic. Gandalf got a lot of play in the old days, even though he was much larger than the 3 and 3/4" format of most of the action figures of the time. His body is constructed of a hollow shell, with articulation only at the shoulders; these days there is a hint of translucence around the beard, and the paint is peeling on his hands. Also, when my niece was three I let her play with some of my sturdier toys, and she surreptitiously chewed on the hatband of Gandalf's pointy hat.
A few years before Peter Jackson's The Lord of the Rings movies came out, the Toy Vault company started to run a line of Middle-Earth action figures. There were only eight figures (with variants), and the Jackson movies and their merchandising effectively knocked this line off the perch, but while it was going I got every one I could. This included three versions of Gandalf: a basic Gandalf the Grey, an "Unexpected Party" Gandalf in a fancy cloak, and a Gandalf the White. They all came with a pipe, pouch, pointy hat, sword and scabbard. The Gandalf the White's staff was different. Instead of looking like a gnarly hooked root like the other two, it was thin, twisted, black, and thorny, which I always thought was a peculiar design choice for a good wizard's staff.
And now I find that DC Universe/Justice League Unlimited has come out with a new action figure, named, simply, The Wizard. It is, in fact, Shazam, the centuries-old sorcerer who gives the young Billy Batson the power to turn into Captain Marvel whenever he repeats his mystic name. He is the image of wizardry pared down to it's most basic, iconic essentials: the robe, the long white beard, and a certain air of authoritative knowingness. It looks great, has nice flexible potential as far as play goes, and I want it.
In the world of action figure play, the wizard has an interesting niche. He may be an advisory figure, someone who gets the story going and offers advice but has little to doing with the actual working out of the action, or he is opposed on the opposite side by an equal or greater power, or he may be the power that the hero fights and must overcome at great odds. The reason for this is obvious: if his awesome powers are brought into play without opposition the story is over before it has begun. In a simple playing as in any greater imaginative undertaking, the wizard is an excellent stirrer of action.