I have found a Wither Storm addon : r/BedrockAddons

Wither Storm Addon (1.19) - MCPE/Bedrock Mod

Download Wither Storm Mod for Minecraft PE - Wither Storm Mod for MCPE

About: Wither Storm Mod - Addons and Mods (Google Play version

Infielded Wither Storm Mod [Minecraft: Java Edition] [Works In

Cracker's Wither Storm Addon V0.1 Beta

Progress on my Wither Storm addon. I can't get the other two heads to mount the body for some reason. (explanation in comments.) : r/MinecraftCommands

Command Block Recipe for Cracker's Wither Storm Mod Minecraft Data Pack

Storm Wither boss mod for Minecraft PE 1.0.9

Wither storm - Imgflip

Cracker's Wither Storm Mod (1.20.1, 1.19.4) - Eldritch Horror Bosses