I've got a 12oz bag of the peanut variety in my laptop bag right now that's almost gone.
For the record, they are labeled as "Mega M&M's".
They aren't new, really. They first came out as 'Shrek Sized' along with the Shrek2 Movie release. I picked them up not even knowing they were any different (they were on sale). Then after I ran out I bought a regular bag and noticed a difference, not bad, but not as good. I got hooked on them and then they were gone. I almost beat it... Then Shrek2 came out on DVD and I saw them again. I grabbed a bunch of bags and they lasted me quite a few mo's (I eat just a few M&M's a day as a snack, and not every day). And then I ran out.
Anyway, since I didn't see any more shrek movies in the works so I wrote to M&Mco asking about long term availability and got no response. I was happy when I saw them at Target on sale a few weeks ago and I grabbed a couple bags. Honestly, They aren't that much bigger than regular Peanut M&M's, maybe 50% bigger, but, there's more chocolate in the ratio so they are better imo.
I was back at Target last weekend and they didn't have any and I only have 1 bag left. That'll last me a while, but,
It's just candy.