This unexpected item is the Figure Mega Pack. It's released under the 20th Anniversary logo/line, but it is just a re-run. This is a 6 pack of the 3.75 line figures that likely collectors already owned a couple of (thanks to forced rebuys) however, it's at a slightly discounted rate, so if you needed doubles/extras this could be the way to go. You can see Knuckles, Shadow, Sonic, Tails, Silver & Amy inside. This appears in late Nov. at Toys R Us in the USA 2011.
There are multiple versions of the 6-pack that have been released.
In time for the holiday buying season of 2014, here comes another figure multi-pack from Jazwares. This is their usual 3.75 line figure for Knuckles, Shadow, Sonic, Amy & Tails...but instead of adding Metal Sonic (like the previous pack, or Silver, like another pack) they add the 3.75 Werehog. This pack actually saves you money if you had 0 of the figures & were going to have to buy them separately. However, if you already had 2 or 3, it's not as good a deal, at most prices.
These multi packs tend to show up around holiday season, and especially at "Toys R Us Xpress" & outlet stores. If you missed the Werehog at this size (it hasn't been on shelves in ages) this is an ok opportunity to grab him.
This small line Sonic figure is different from the others because both hands are closed fists. This pose is generally available in that "Modern Figures Set Pack" (has 5 or 6 of the 3.75 line figures in there, likely to be a Toys R Us exclusive) but can also appear in those single card package format like you see above. The single card figures (reportedly) can vary a little bit on how they're posed / it may be Jazwares clearing out extra figures, or figures who were originally supposed to be packaged with other things, instead being sold alone on the card like this.