Gillian, please use extreme caution.

snatcher.rb

class Snatcher < BasicObject
  
  C = ::Object.new
  class << C
    def abduct_method(meth, arity)
      ObjectSpace.each_object(Module) do |mod|
        next if mod.kind_of? Class
        if mod.instance_methods.include?(meth)
          return mod.instance_method(meth)
        end
      end
      nil
    end
  end

  def method_missing(meth, *args, &blk)
    if method = C.abduct_method(meth, args.length)
      (class << self; self; end).send(:define_method, meth, method)
      __send__(meth, *args, &blk)
    else
      super
    end
  end

end

# Sad face: you can't abduct UnboundMethods from classes... as far as I can tell so far.
module Abductee

  def bite
    scream
  end

end

module Abductee2

  def scream
    "ow!"
  end

end

# I've got you now, SNATCHER scum!
puts Snatcher.new.bite