Wonderful job! I really like the one with Kermit and Rizzo and your Miss Piggy was fantastic! Looks like you have mastered Kermit's features as well, something I'm still working on. The one thing I noticed was the spelling of Rowlf's name. It's a common error, but he is indeed a Rowlf and not a Ralph.
Other than that, keep up the excellent work! I'll look forward to seeing more artwork from you.
P.S. I'm not a tech person, so I was wondering, if you'd be so kind, if you or anyone else could explain how that works. I have some drawings that I would love to share but I have no idea how to get them online.