Traits

Your Perfpal's legs can be replaced with a mermaid's tail. The tail must be a realistic length. 
The tail must be that of a fish, not another aquatic life form.
(Aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits)

(This allows for an alternate "form" if you'd like for your Perfpal to have access to legs still.)

Gills can be placed on any plush part of the body. They are purely cosmetic and have nothing to do with a Perfpal's breathing.

Permanent seaweed growth is possible on any part of the body. Seaweed can be any color and any length. 

Can be added in any amount on any part of your Perfpal, excluding on the hooves directly. The fins can come from any marine animal that has fins. They must be a realistic length.

Waterbed stuffing allows for your Perfpal to be filled with water instead of having regular stuffing. This causes the Perfpal to move a bit differently. The water can be any color. (Named after the furniture term and not the ecology term)

Using the supply from any stuffing that provides a liquid, your Perfpal can have holes in their pawpad that allow liquid to pass through. 

Gives your Perfpal wings from any tropical bird. These wings can be any length and will allow your Perfpal to fly. They must be on the back unless you have another item that allows wings to move.

Your Perfpal can have any type and length of monkey tail.

Allows for permanent vine growth on your Perfpal. The vines can grow leaves on them. They can be any length and grow from anywhere on the body.

Your Perfpal's stuffing is changed to a tank. The tank can be filled with any kind of liquid. Most commonly, Perfpals are filled with water and other aquarium decorations. This trait is commonly paired with the watering can paws from the same thread.

Changes your Perfpal's entire face with an electronic screen. This screen can display whatever you'd like. Perfpals often have electronic faces to display their emotions.

Pawpads on the Perfpal can light up any color that the user chooses. They make a clicking sound when interacting with anything.

The tail of the Perfpal has been turned into a charger! The charger is a long cord with either a plug-in or outlet. It can be curly and must be a reasonable size.

Gives your Perfpal a CD player on their belly. It can be horizontal and go into the Perfpal's body, or vertical to display the disk. 

The perfpal is stuffed with wires. The wires can be any color and any length.