class Animal 
  def initialize name
    @name = name 
  end
end

class Dog 
  def initialize color
    super
    @color = color
  end
end

bruno = Dog.new "brown"
p bruno #=> < @name = "brown", @color = "brown" >

in addition to the default behavior, super automatically forwards the arguments that were passed to the method from which super is called (initialize method in Dog class)

Right way!

...
class Dog
  def initialize name, color
    super #=> wrong number of arguments
    super name
    @color = color
  end
end

bruno = Dog.new "bruno", "brown"
p bruno #=> < @name = "bruno", @color = "brown" >