Pokemon OOP

pokemon.rb

class Pokemon
    attr_reader :type, :hp
    attr_accessor :name

    def initialize
        @type = nil
        @hp = 10
        @name = nil
        @@message = "Pokemon is a fun game"
    end

    def tackle enemy
        puts "#{@name} did 4 hp damage to #{enemy.name}"
        enemy.decreaseHP 4
    end

    def decreaseHP num
        @hp = @hp - num
        if (@hp < -3)
            puts "STOP HE'S ALREADY DEAD"
        end
    end

    def self.message
        @@message
    end
end

class GrassPokemon < Pokemon
    def initialize
        super
        @type = 'grass'
    end
end

class WaterPokemon < Pokemon
end

class FirePokemon < Pokemon
end

class Bulbasaur < GrassPokemon
    # implement some attacks
    # initialize
    #   - set the initial HP
    def vineWhip
        puts "#{@name} did 9 hp damage"
    end
end

class Squirtle < GrassPokemon
    # implement some attacks
    # initialize
    #   - set the initial HP
end

class Charmeleon < FirePokemon
    # implement some attacks
    # initialize
    #   - set the initial HP
end


kanye = Bulbasaur.new
jayz = Bulbasaur.new
skepta = Charmeleon.new

kanye.name = "Kanye West"
jayz.name = "Jay Z"
skepta.name = "Skepta"

kanye.tackle skepta

puts skepta.hp
jayz.tackle skepta
puts skepta.hp

kanye.tackle skepta
puts skepta.hp

jayz.tackle skepta
puts skepta.hp