Don't know credits

_G.HitBoxSize = Vector3.new(50, 50, 50)

game:service('RunService').RenderStepped:connect(function()
for i, v in pairs(game.Workspace.Camera.GameElementContainer.HITBOXES:GetDescendants()) do
if v:IsA('Part') and v.Size ~= _G.HitBoxSize and v.Transparency ~= 0 and v.Name == 'Head' then v.Size = _G.HitBoxSize
v.Transparency = 0
end
end
end)