From The Wajas Wiki

Tentacles are a type of Mutation that can be added to a waja either during custom creation or through use of Tentacles DNA. It can also be added by using a Mutation Pear. When creating a custom with Tentacles, or adding them to an existing waja with a DNA, you may choose their color.

Mutation Appearance

All examples feature wajas with FF0000 (pure red) Tentacles. However, this mutation can come in any Hex Color as well as any Texture.