Butterfly or Sea Creature?

This is Elizabeth Zimmerman's Butterfly Jacket - I hope! The two fronts have just been united and I'm knitting up the back. I'm not keen on the yarn - it's a big ball of Robin I bought from the market when I first started knitting. I prefer vintage thrift shop finds to cheap acrylic, and don't buy new acrylic now but it doesn't matter. Some deep pessimism tells me that this is going to be a test garment rather than something I'll actually wear, so it won't matter any more than it mattered that I knit a 50's 'Ladies Jacket' in vile green Robin double knit yarn. It would have been unwearable whatever it was knitted in.