Gold/Silver has a new way of evolving. A few Pokemon evolves by mood. This means that you have to treat it properly and keep it happy until it evolves. Here is a list of Pokemon that evolves by mood:

Pokémon Evolving by Mood
#	Pokemon	Evolves into
42	Golbat	Crobat
113	Chansey	Blissey
133	Eevee	Espeon or Umbreon
172	Pichu	Pikachu
173	Cleffa	Clefairy
174	Igglybuff	Jigglypuff
175	Togepi	Togetic

How do you keep your Pokemon happy until it evolves? Refer to this chart here:

Things that Improves your Pokemon’s Tameness

- Using it in Battle

- Leveling it up

- Giving items to hold

- Using healing items on it

- Reviving it as soon as it faints

- Taking it to the Pokemon Salon

- Taking it to Blue’s sister in Pallet Town 3:00 to 4:00 (Day)

- Keeping it in your Party

And ways that will upset your Pokemon...

Things that Worsen your Pokemon’s Tameness

- Not using it in battle

- Leaving it in the PC

- Using "Bitter" items on it

- Leaving it in fainted condition

- Leaving it sick or wounded

To find out how well your Pokemon likes you, go just above the Goldenrod City Mart and look inside a house near it (just above the Bicycle Shop) to find a lady that will tell you how well your Pokemon likes you. If she says "It really seems to trust you", you know your Pokemon is going to evolve soon!

Eevee may evolve into Espeon and Umbreon. If you did the following, keeping your Eevee as happy as possible, it will depend on what time of day it evolves. If Eevee evolves in the Morning or Day time, it will evolve into Espeon. However, if Eevee evolves in the Night, Eevee will evolve into Umbreon. If Eevee evolves when it’s at the wrong time of day, just cancel it (pressing B) and raise it up a level when it’s the time you want Eevee to evolve to get which ever Pokemon you want. If you want another Eevee, breed it with a Ditto if your Eevee/Espeon/Umbreon is male at the couple’s Day Care to recieve another Eevee to raise all over again.