Hello, I'm an expert in the field of Pokémon breeding. When it comes to breeding Beldum with a Ditto, it's important to understand how the Pokémon breeding mechanics work in the games.

In the Pokémon games, Beldum is a Steel and Psychic-type Pokémon, while Ditto is a Normal-type Pokémon. Breeding in the Pokémon games involves two main methods: breeding through a Day Care service, where two Pokémon are left together to produce an egg, and the Masuda Method, which involves breeding two Pokémon from different language games to increase the chances of getting a Shiny Pokémon or a Pokémon with an Ability that the mother does not naturally have.

Beldum can only be bred in the games where it is in the same Egg Group as the other Pokémon. Beldum is part of the Mineral Egg Group. Ditto, on the other hand, is unique in that it is not part of any specific Egg Group but can breed with any Pokémon that is not in the Undiscovered or Baby-Only Egg Groups.

Given that Ditto can breed with Pokémon from any Egg Group it is not a part of, and Beldum is part of the Mineral Egg Group, you can indeed breed a Beldum with a Ditto. When you do so, the resulting egg will be of the Beldum's Egg Group, and it will hatch into a Beldum.

Here's the translation in Chinese:

你好，我是精灵宝可梦（Pokémon）繁殖领域的专家。当谈到用百变怪（Ditto）和铁哑铃（Beldum）进行繁殖时，了解游戏中的精灵宝可梦繁殖机制非常重要。

在精灵宝可梦游戏中，铁哑铃是钢系和超能力系的宝可梦，而百变怪是普通系的宝可梦。游戏中的繁殖主要有两种方式：一种是通过托儿所服务进行繁殖，将两只宝可梦放在一起产生蛋；另一种是马萨达方法，涉及将来自不同语言游戏的两只宝可梦进行繁殖，以增加获得闪光宝可梦或具有母亲本不具备的特性的宝可梦的几率。

铁哑铃只能在它与其他宝可梦在同一个宝可梦蛋群的游戏中进行繁殖。铁哑铃属于矿物蛋群。另一方面，百变怪是独特的，因为它不属于任何特定的宝可梦蛋群，但可以与不属于未发现或仅宝宝宝可梦蛋群的任何宝可梦繁殖。

鉴于百变怪可以与它不所属的任何宝可梦蛋群的宝可梦繁殖，而铁哑铃是矿物蛋群的一部分，你确实可以用百变怪和铁哑铃进行繁殖。这样做时，生成的蛋将是铁哑铃的宝可梦蛋群，并且会孵化成铁哑铃。

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If Beldum was mated with a Ditto, then a Beldum would hatch.) For a Bagon to learn Hydro Pump (it's possible!), the male Pokemon breeding with the female Bagon, Shelgon, or Salamence must know Hydro Pump. The father passes on attacks to the egg and the mother produces the egg. YOU CAN BREED BELDUM EGGS END OF STORY.read more >>