Need help manipulating random inputs for my monsters in the game we are building

import random

COLORS = ['red', 'yellow', 'blue', 'green']


class Monster(object):
  min_hp = 1
  max_hp = 1
  min_exp = 1
  max_exp = 1
  weapon = 'sword'
  sound = 'roar'



  def __init__(self, **kwargs):
    self.hp = random.randint(self.min_hp, self.max_hp)
    self.exp = random.randint(self.min_exp, self.max_exp)
    self.color = random.choice(COLORS)

    for key, value in kwargs.items():
      setattr(self, key, value)


  def __str__(self):
    return '{} {}, HP: {}, XP {}'.format(self.color.title(),
                                         self.__class__.__name__,
                                         self.hp,
                                         self.exp)

  def battlecry(self):
    return self.sound.upper()


class Goblin(Monster):#goblin is subclass that will have all monster attributes
  max_hp = 4
  max_exp = 2
  sound = 'eee'


class Troll(Monster):
  min_hp = 3
  max_hp = 5
  min_exp = 2
  max_exp = 6
  sound = 'snarl'


class Dragon(Monster):
  min_hp = 5
  max_hp = 10
  if Monster.hp > 7:
    min_exp = 10
  else:
    min_exp = 6
  max_exp = 10

  sound = 'gaaaaoooooo'