Avid and Metric Halo is currently giving away MH's Thump Percussive Subharmonic Plugin (PT AAX only) which can be used "....to enhance or transform your drum tracks. Add low end to percussive tracks, or re-create classic drum synth sounds...". To get Thump just fill out the form on this page.
Russ Hughes (Pro-Tools-Expert.com) made the following video showing some of the ways Thump can be used in a session.
Pro-Tools-Expert.com is also giving away a copy of the Metric Halo Production Bundle (which I use and highly recommend). The Production Bundle is available in AAX and AU.
You can download a 30 day trial here.