Becoming a Mercreature: Tail Design Considerations

The major part of our mercreature costume is the tail! By which we give up our legs for...well...nothing else. I did not get gills or hypnotic singing out of this deal. Just can't use my legs. For this, I'm going through what I've thought about when designing potential tails for my mercreatures. 

For this exercise, I am going to consider choices for a Koi fish mermaid, an orca mermaid, a selkie, and an Eldritch Horror...aka a cephalopod. 

Basic Tail Anatomy 

This isn't going to be the technical anatomy of aquatic life, but just the parts of the costume. The tail is made up of the body (usually the tube portion that fuses your legs together), the fluke (Caudal/tail fin), and the waistband at the very basic level. You can add other fins that correlate to your sea creature (things like a dorsal fin or pectoral fins or pelvic fins). 

But for this, we do want to get some guidance from references. 

(Pics of Butterfly Koi, Orca, Seal, and giant squid)

Tail Body

For most of our creature designs, the tail is going to be a tube shape that comes up to our waist. As far as a "pattern" goes it's pretty basic. (Of course, there is some nuance.) 

The creation of a pattern for your tale is as simple as sitting on a roll of wrapping paper with your legs together and tracing around your legs. 

You also have the option to create a mermaid tail duct tape dummy. 

This dummy form is pretty essential if you are making a latex or silicone tail. It's also essential for creating paneling for creature markings and such. 

Tail Materials 

The big design decision is what would be the best material to use for the tail. If you are new to mermaiding and tail making, it is highly recommended that you start with a fabric tail or a sort of hybrid between a fabric or silicone tail. (I have tutorials listed for all kinds of tails linked below.)

With our examples, the koi mermaid we have the most flexibility with. She would be great as a fabric tail or a silicone tail. 

The orca is probably best as a fabric tail using spandex. I have not really found many resources for making dolphin skin in silicone but I'm sure it's possible. 

The selkie I would play with water friendly stretch velvet to give it a bit more of a fur texture. 

The squid I might look at something more rubberized like scuba fabric or neoprene. But likely, I'd go with spandex again for the base. 

From there it's like sewing a sock or tube of fabric. Most of the time you are going to have seams along the sides. I'm sure there are ways to make it a single seam, but let's be real, the side seams are going to be a thing. 

In our examples, this will be true for the koi, orca, and selkie models. However, our lovely octopus/squid monster is not a tube. They will be leggings since for this design we're making a swim skirt. 

Body Markings

How you add the creature's markings is going to depend on what shape the pattern is in and what material you are using. 

For our fabric tails, we have many options! Using an orca as an example, we can use clever paneling or get our fabric professionally printed with the correct pattern. 

The koi fish in fabric might be best as a pre-printed fabric, but we may use applique or fabric paint. 

The selkie will easily need to be painted and I might use some dye on the squid leggings. 

Silicone is a usually either painting or the scales are dyed prior to casting the scale or scale sheets. The Koi patter is easy enough if you are making a tail one scale at a time. (Tedious but usually worth it. I like how these particular tails look.)

Fluke Shape 

A defining feature for a lot of mermaid tails and creatures is the shape of their tail fin or fluke. Yes, there's a difference between fluke and fin. Flukes move up and down, caudal fins side to side. And since we're all mammalian mermaids, it's always going to be an up and down kind of tail...so technically it's always a fluke. I'm on a tangent. Let's get back to the shapes. 

So for our cetaceans and fish mermaids, we're looking at very modified monofins or flippers stuck together into a single shape. Look at references of the creature to get close to the shape. The orca is easily defined by the tail but the butterfly koi is a bit stringy in a sense. 

The selkie and squid are special cases. The squid can use small normal flippers and you could do something similar for the selkie. You could also make a monofin for the selkie but it won't be as effective as the fish/cetacean monofin. 

It's important to mention that materials will make a big impact here. 

The Orca, Selkie and Squid are fine with creating a fabric covering for the monofin that is part of the main body of the tail. 

The koi fish may look better with a silicone or latex tail so we can create some of the unique shape with latex.

Adding Other Fins

Some of our mercreature have many fins and you can get quite stylish with them. 

For more fishy mermaids, using a sheer fabric like nylon, tulle or gauze make for some nice flowing fins that can go along the side seams, down the backside, around the waist or acting as pectoral or pelvic fins. 

It's also quite popular to create these out of silicone or latex to attach to a fabric or silicone tail after the main body. 

However, our orca has a very distinctive feature or two, a tall dorsal fin and large paddle-like pectoral fins. The pectoral fins are easy enough to incorporate into the pattern of the tail before cutting fabric. They will need to be filled with swim foam or plastic to hold the shape. But the iconic dorsal fin needs to be placed well. You may need to cut a hole in the backside to insert a fabric dorsal fin. 

Or think about your design and maybe move these fins to other parts of the costume such as the middle of your back! Not everything needs to be on the tail! 

For our squid/octopus, we have to consider the tentacles. They need to carry some weight but not weigh down the swimmer. The tentacles are either going to be part of a larger swim dress pattern or a skirt pattern. Weighting the tips of the tentacles may be done by inserting cotton, beans, sand bags, or thermoplastic. Then again, if you use latex or silicone for the suction cups then the weight might handle itself. Or you can sew the tentacles as flat like the picture below. 

Example of an octopus swim dress

Honestly, there's a lot to consider when designing a tail for your mermaid. Checking out examples is the best way to go about it. Below I have listed tutorials on various methods for making mermaid tails.

References

Fabric Tail Sewing Tutorial (Instructables)

Fluke Tutorial (Wikihow)

Diving Fins into Flukes Tutorial

Silicone Tail Tutorial (Instructables) 

Hybrid Fabric and Silicone Tail Video

Silicone Tail Video Tutorials

Latex Tail Tutorial

Adding Silicone Fins to Fabric Tails (Etsy $)

Next: Tail Markings and Adding Fins