Mudstream

Name: Mudstream

Pronouns: He/him

Abilities: Flying, camouflage in mud, mud and water powers

Species: Some sort of fox, seagull hybrid mud thing

Age: 32

Mudstream was a the original version of Sandwave but according to Celeste, he was a defect so he got locked up underground with Rain and Mirage. Mudstream got powered by Rain and was finally returned to his healthy state.

So you can say Sandwave is really Sandwave 2.0

Mudstream represents/is an allegory for something very specific. Imagine a superhero team, or a show cast, or a friend group or some group of tightly knit people. One of them is a bit of a black sheep. So, the others push them away. Someone new enters and soon enough, that new person is kind of known as the "replacement" of the black sheep. Mudstream represents that replaced person.