What's the deal with Minecraft: Story Mode's Wither Storm?

Almost everything in Minecraft: Story Mode exists in vanilla Minecraft or resource packs - except the Wither Storm.

if only the wither storm had deeper lore instead of just wither

Minecraft: Story Mode' Episode 2: Assembly Required Review

Minecraft: Story Mode - A Telltale Games Series - 'A Block and a

Who gave the witherstorm such a fire theme #minecraftstorymode

Steam Workshop::Minecraft Story mode: Wither Storm Sounds

Minecraft: Story Mode review

Minecraft: Story Mode drops the Wither Storm Finale trailer

Minecraft Story Episode 1: Thief And Wither Monster

Chapter 6 - Episode 4 - Minecraft: Story Mode - A Telltale Games

Cracker's Wither Storm Mod - Minecraft Mods - CurseForge

I made the Wither Storm from Minecraft Story Mode!