I'll give some examples of Pokémon that are specially and physically defensive (or both.)
Shuckle
![enter image description here](https://www.serebii.net/xy/pokemon/213.png)
With the highest Sp Defense and tied higest Defense this thing could arguably be one of the best defensive Pokémon.
Its only really useful ability however is Contrary. A moveset with this ability could be:
- Shell Smash
- Infestation
- Toxic
- Rest
This is also the set Pimpnite used in one of his sweeps so that is an example of how it works.
Regirock/Regice
![enter image description here](https://www.serebii.net/xy/pokemon/377.png)
![enter image description here](https://www.serebii.net/xy/pokemon/378.png)
Another two Pokémon that have one of the highest in both their designated defences.
Regirock is often used for setting up here is a common set for it:
- Stealth Rocks
- Substitute
- Stone Edge/Earthquake
- Drain Punch
You could also have Regirock hold the Assault Vest and replace Stealth Rocks and Substitute with Ice Punch and Power-Up Punch
Regice however can use this set:
- Explosion
- Ice Beam/Blizzard
- Toxic/Thunder Wave
- Thunderbolt
These are just three examples of defensive Pokémon that can do damage as well.
If you wanted one for just pure stalling then Dusknoir would be a very good choice.
If you would like more just ask and I'll add more sets :)