Jessica Walter has signed on to appear in an upcoming episode of CBS' The Big Bang Theory, a series rep confirms to THR.

The Arrested Development alum, who currently lends her voice to FX's animated comedy Archer, will take on the role of Barbara, a rich donor whose grant to the university science department relies on Leonard.

Walter's episode is scheduled to air in February.

http://www.hollywoodreporter.com/blogs/live-feed/big-bang-theory-adds-arrested-69694

I don't know if anyone else has been watchiong Archer - but I just discovered it a couple of weeks ago and it is AWESOME!

...and of course Jessica Walters is hilarious in it :)

its sort of like an Arrested development on crack, with deformed children and spies in it.