My 4yo daughter wanted to be Kermit for Halloween, so I used vintage Vogue patterns I found on eBay to make these costumes for my daughter, nieces, and nephew!
Kermit is made entirely out of felt, with the eyes made of a styrofoam ball cut in half, covered in a white cotton scrap, and sewn in place. Fozzie's body and head are made of fleece (the cheap stuff that everyone makes tie-blankets out of!). His hat is made of a felt scrap, sewn in place. His nose is a styrofoam egg that I had to shape before covering in pink felt and sewing in place. For his tie, I googled fabric "white with pink polka dots" because they didn't carry any and I didn't want to have to drawn the dots on, although you could with a pink Sharpie. Animal's pants are pleather and his vest is felt with costume satin appliquéd over it. The head is just yarn sewn on in individual clumps. Piggy's dress is more costume satin. Her head piece is also mostly yarn. The trim on her dress and headband were probably the most expensive part of all four of these costumes! I hope this is a detailed enough description!