Pepe appears in a few different places. He's got a property of his own on the board (in the red section along with Sam the Eagle and the Swedish Chef), he's on at least one Chicken/Penguin card, and he shows up on the platform in the box, mingling with a handful of other Muppet characters. That's all I can remember off-hand. There's a great mix of old and new characters in the game, from Lew Zealand and the Muppet Newsman to Johnny Fiama and Sal.
I'd have to guess Marvin Suggs is the most obscure character in the game, but it might be a close race for that title. He appears on one of the Chicken/Penguin cards with his Muppephones.
I did a lot of work on designing the Muppets Monopoly money and it DOES have characters on each of the bills. The six higest denominations feature the same characters as the tokens: Kermit's on the $500, Miss Piggy's on the $100, Animal's on the $50, Fozzie's on the $20, Gonzo's on the $10, and The Swedish Chef's on the $5. Lastly, but certainly not least, I put Sam the Eagle on the $1, since the patriotic bird just seemed to me the perfect fit for a portrait on currency. I thought Sam would get a real kick out of being on a one dollar bill.
There's properties on the board for each of the major Muppet players (Fozzie's Comedy Club, Gonzo's Daredevil Stunt Show, Rowlf's Recording Studio), as well as a few rarer characters (Beaureguard's Supply Closet, Robin's Lilypad). There's also the Swinetrek, Muppet Labs, Electric Mayhem's Stage, etc. I'm not sure if you'd want me to list ALL the properties in the game here, but I probably could from memory.
As for the box top, it no longer has the game board featured on it and instead has... actually, I MIGHT be able to SHOW it to you. Sometime in the next few weeks, there's a chance I could give you all an early first look at the final box top. I can't guarantee anything... but there's a chance.
This has been USAopoly's first game featuring the Muppets and it's really been a blast to work on. I hope you all have as much fun playing it as we did making it.