Swan Candlesticks, Fenton
This is Fenton's mold number 5172 and first appeared in amethyst in their 1973 catalog. They're about 6 1/2 inches tall. I've only heard of them in amethyst. The pair shown here sold on eBay in 2004 for $66. Other pairs have sold for $31, $41, and $65. Individual examples will sell for a little less than half of what a pair does.