Physical Tanks

Mega Aggron

Mega Aggron has one of the highest defenses in the entire game. Not only is it bulky in Defense, but it is also a very powerful attacker. Because of its already high Defense, it's another option to raise EVs in its Sp. Defense to make it a neutral wall. The EV Spread should definitely be in its HP, and some invested in Attack, Defense, and Sp. Defense. With its ability Filter, it allows Mega Aggron to absorb its weaknesses better.

Mega Aggron's moveset has a variety of possibilities. Its best STAB more is Iron Head or Heavy Slam, but Iron Head is more popular because of the consistent damage. Other moves are for effective coverage. Curse is a possibility because it raises Mega Aggron's Attack and Defense, and the Speed drop isn't too much of a big deal.

Move 1: Heavy Slam/Iron Head	Move 2: Curse/Aqua Tail/Ice Punch
Move 3: Earthquake/Stone Edge	Move 4: Curse/Aqua Tail/Ice Punch

Weezing

Weezing is a relatively popular choice as a physical tank. Not only does it have only one weakness because of Levitate, but it can still absorb hits very well. Weezing should hold a Black Sludge to function like Leftovers. EVs should be invested in Defense because it's still not the best, so it is purposely weaker against special attacks. HP should also be invested, but Sp. Attack should not be as much.

Weezing's moveset revolves around weakening your opponents down so their attacks can be taken while whittling down their health. Sludge Bomb is obviously for a STAB offensive move, and Flamethrower is for coverage, namely against Steel types. Pain Split is to help Weezing recover health along with Black Sludge, and Will-O-Wisp is to decrease your foe's health while cutting their Attack.

Move 1: Sludge Bomb	Move 2: Flamethrower
Move 3: Pain Split	Move 4: Will-O-Wisp

Quagsire

Quagsire is not as popular as other choices, but like Weezing, has only one weakness. Unfortunately, since Grass is 4x effective, Quagire is pretty much doomed against it. It should hold Leftovers to help with health, and EVs should be invested in HP, Attack, and Defense. Another option for Quagsire is for it to be a neutral defense wall, in which case Sp. Defense needs to be raised. Impish is its best nature, although Relaxed is another option because of its already small Speed.

A big part of Quasire's tanky trait is its capability of using Recover, which is very significant for a tank. The only reason Aqua Tail would be chosen over Waterfall is for its power, and since Quarsire is very slow, the flinching chance of Waterfall doesn't matter. Earthquake and Stone Edge are for coverage, but Earthquake should be better because of STAB. Curse is to raise Quagsire's Attack and Defense. The only type that resists both Water and Ground is Grass, and Quagsire should be immediately swapped if faced against a Grass type.

Move 1: Waterfall/Aqua Tail	Move 2: Eathquake/Stone Edge
Move 3: Curse	Move 4: Recover