On the 28th of September 2011, coninciding with the sale of Issue 11, an additional second national set of 180 cards was available under the expansion name of "Extreme". These were available with Doctor Who Monster Invasion magazine or by separate purchase. Packs included a mix of cards; 150 Common cards, 18 Rare, 6 Super Rare, 5 Ultra Rare and one Infinite card. These cards followed the same categories as established in the previous releases.

The new infinite card, which now, appears to be rarer than Assimilate, depicts the silence using its electricity attack and unlike the previous two lenticular cards, this one was portrait rather than landscape.

Accompanying the 'Extreme' set was a Doctor Autograph card which came free with Issue 11. There were two other autograph cards which were Rory and Amy. The Rory autograph card was guarunteed in the second released tin of Monster Invasion cards where the Amy autograph card was only available to subscribers who opted in to buy one. These cards are also incredibly rare as there was an incredibly limited print run of approximately 5,000.