Battle Moveset

A Good Moveset for Umbreon would have to be this:

Attacks:

Mean Look
Toxic
Baton Pass
Wish

Items Attached:

LeftOvers

Preferred Nature:

Bold

Strategy Using Umbreon

You may notice that Umbreon is a defensive stat pokemon, with pretty poor offensive stats. Putting any offensive attacks on Umbreon is somewhat foolish for any serious competition.
This is the baton passing moveset, with the fourth move being changeable with these moves: Taunt/Substitute/Confuse ray/Moonlight/Rest. Set up a mean look, maybe poison your opponent with toxic then baton pass to a pokemon with the advantage, or stay around to tank.
You can use wish to restore your own HP later in the battle, which works very well with Baton pass. Another possible moveset is: Mean look, Screech, Confuse Ray, with the fourth move being something to restore HP.
Umbreon, overall, has one of the best tanking base stats available, and although the best way to go about KOing Umbreon would be to capitalise on its bug and fighting weakness’, there are many ways to disable its offensive abilities entirely.
Firstly, you’ll notice its lack of effective offensive moves and how most effective Umbreon sets carry no direct ‘damaging’ attack. Instead they’ll use moves such as Toxic and Confuse Ray combined with Mean Look.
- Substitute will completely screw up an Umbreon’s chances of doing damage (even if it does carry direct damaging techniques since it has such weak attack stats) and will most likely give you a free turn to use a stat boosting move. This could also incorporated Focus Punch, which not only will do a lot of base damage but also score a super effective hit.
- Taunt, will also screw up a typical Umbreon’s move set, preventing the use of moves such as Mean Look (its signature technique) and Toxic. The turn afterwards it’ll most likely cause a switch or else Umbreon will be forced to use struggle (or a direct damage attack which won’t do much due to the aforementioned weak attack stats).
- Toxi-stalling, pretty much the same technique that a non-Baton Passing Umbreon uses. Use one of the above techniques and then inflict Toxic. Stall until the opponent has the sense to switch rather than allow Umbreon to faint.
- All out offensive. In basics, use powerful STAB attacks such as Heracross’s Megahorn or Machamp’s Cross Chop. Although this may not score an automatic knockout it’ll most likely knock out Umbreon after a couple of uses. The downside of this strategy is it leaves you open to being hit by one of Umbreon’s annoyance techniques which could lead to your Pokémon’s downfall.
Again, thanks to Onimusha for his contributions to this strategy and moveset.

EV Corner:

Max out the EVs in HP for Umbreon with any remaining in Defense & Special Defense

Strategy Against Umbreon

Umbreon' Defenses are way above average but it's physical is slightly lower so a Physical Volley or a Fighting Type Volley should work

Contest Moveset

A good Contest Moveset for Umbreon would have to be this for the Tough Contest best with Impish, Lax, Relaxed or Bold Nature:

Attacks:

Quick Attack
Swift
Curse
Flail

Items Attached:

Yellow Scarf

Strategy Using Umbreon

If you do the attacks in this following order you should have very few problems; 1st - Quick attack, 2nd - Swift, 3rd - Curse, 4th - Flail, 5th - Quick Attack

Locations in Games

Ruby/Sapphire/Emerald Trade from C/FR/LG Colosseum Starter Pokémon Fire Red/Leaf Green Evolve Eevee

Animé Appearences

Umbreon has had a few Animé Appearences. They were under the control of Gary or one of the Eevee Sisters. The rest are cameos Episode 173: Power Play! Episode 185: Trouble's Brewing! Episode 228: Espeon Not Include! Episode 271: The Ties That Bind! Special 16: Pokémon Researcher Gary & The Revived Aerodactyl!