According to Greek mythology, Triton was the son and messenger of Poseidon, and had the tail of a merman. With his conch shell, he could quiet the waves with a single breath. The Greeks depicted him with two fish tails. King Triton also appears as one of the characters in the Disney cartoon "The Little Mermaid." In this role, he is the Sea King and the father of Ariel, the main character. If you are of grand physique, King Triton might be a fun costume to put together for your next Halloween party.
Cut the shape of a trident out of yellow poster board (just the three blades). Run this shape through a laminator. If you don't have one, you can find one at most craft or teacher's supply shops.
Attach the laminated trident blades to the head of your broom, using clear packing tape to obscure the head and hold the blades in place.
Spray-paint the shaft of the broom white or yellow. Allow up to 24 hours to dry, depending on the brand of paint.
Print a beard template on computer paper. Many are available online. King Triton traditionally has a long, flowing beard, but match the beard to fit your personal preferences.
Place the template on the white craft felt. Draw a line around the template on the felt, and then cut out the felt.
Apply spirit gum to the side of the felt that will adhere to your face. Spirit gum is available at most costume shops and many craft shops.
Find a pair of green or blue wind trousers, and find craft fabric to match the colour. Cut wavy shapes out of the fabric.
Attach the pieces of fabric to the wind trousers, either with clear packing tape or safety pins. The pins will hold more effectively, but leaving that many holes in a pair of wind trousers will reduce their weather-resistance.
Slide on the trousers (gently if you've pinned them). Now your costume is complete.
If you don't mind having your legs more entangled, you can convert a pair of trousers to a mermaid tail.