Dreadwheel are a type of wheel skeleton found in Act 1 and Act 6. They are a skeleton fused with a wooden wheel which charge towards the player and attack.
In Blight, there is a variant of this monster, Blighted Dreadwheel.
3.18.0b Patch Notes: Dreadwheel Monsters can no longer be found with Flame, Storm or Frost Strider modifiers.