Arturia have been giving away the MINI Filter V - which is a recreation of the classic Moog ladder filter together with an LFO, Envelope follower and 8 step Sequencer. They've extended the give away period to the 29th December in celebration of the holiday period.
The MINIFILTER V comes in all the usual plug-in formats, all you need to do is to sign in to your Arturia account or create one if you don't already have one, then you can download it for gratis.