This core is really very simple, but it works very well. Krookodile can kick off any Pokémon that Zapdos can't touch (except Mamoswine and Florges). Knock Off is Krookodile's first STAB, with Dread Plate it becomes more dangerous than Earthquake if your opponent has no Item. Earthquake can do a lot in any Pokémon that can't resist it, and pressure out so many Pokémon, such as Nidoqueen and Nidoking. Stealth Rock is essential in this Metagame. Pursuit is a good move to trap Chandelure and other Pokémon that are pressurized, but Taunt can replace it, because everyone hate Stall Cores actually. The 240 EV's in Speed and a Jolly Nature are used to outspeed any Pokemon with 80-90 of Speed, such as Roserade, Toxicroak, Lucario and Nidoking, this Spread can outspeed Band Adamant Entei, too. The other EV's are used to increase it's offensive power and it's bulk, you can run an Adamant Nature with 252 EV's in Speed too, but it isn't so effective. Intimidate is Krookodile's Ability because if a Lucario buffs Swords Dance in front of it, it will be +1, but he can't kill you with Extremme Speed and ou can OHKO it with Earthquake. Zapdos has to relevant sets in this core: the LO 3 Attacks + Roost or the Choice Specs, so, I'll explain the two. Firstly the LO 3 Attacks + Roost: It is a really very effective set with Krookodile, Thunderbolt is the main STAB, that can hurt any Pokémon of your opponent with a high damage and it can 2HKO any Bulky Water that isn't immune to it. Heat Wave can do a lot in Physically Defensive Steel-Types (Forretress and Aggron-Mega), in Grass-Types (Whimsicott and Shaymin) and in Bug-Types (Escavalier and Heracross), and all these Pokémon are so dangerous to Krookodile, that will struggle to it. Now, we have one indecision: Hidden Power [Ice] or Hidden Power [Grass]? I like the two, but it depends with the team that you are using: If you are so many weak to Swampert and Seismitoad, you can run Hidden Power [Grass]. But, if you are weak to Gligar, Hydreigon, Salamence and Mega Sceptile, you can run Hidden Power [Ice]. The most of time, I use Hidden Power [Grass], because those four Pokémon are walled by any Fairy-Type with ease, such as Florges and Whimsicott. Roost is Zapdos recovery move, that can heal 50% of it's life in a free turn. Life Orb can increase your damage in 1.3, but it will make you recoil, but you have Roost, so it is OK. Now, the Choice Specs Set: This set has a better offensive presence and it has not recoil, but, Zapdos has no reliable recovery and it is always limited to use the first attack that you choose, so it has a big weakness to Stealth Rock, because the only way to recover your health is use Healing Wish/Lunar Dance/Wish, and if you want to use another attack, you need to switch Zapdos. Anyway, Thunderbolt is the main STAB, that can hurt any Pokémon really hard. Heat Wave can do a lot in any Bug-, Grass- or Steel-Type. We have the same indecision, again: HP Grass or HP Ice? It depends of your team, but in this set, i recommend to use Hidden Power [Ice], because that are so much Pokémon that can deal with Swampert, like Hidden Power [Grass] does. Volt Switch is the "help button" move. Zapdos is so fast, so it can outspeed a lot of Pokémon in the tier and run. For the both sets, we have the same ability and the same EV Spread. Static Zapdos is really very fun to use paired with Krookodile, because it can punish U-Turn users, Fighting-Types or Outrage Salamence. 252 Speed with a Timid Nature are used to maximize it's speed and Speed Tie with Salamence.