Some slow and decently bulky Pokemon that can learn it are:
- Politoed (more specially bulky)
- Meloetta (though lacking on the physical side a bit)
- Wigglytuff (has a lot of HP, you can give it an item boosting its defenses)
These all lack a bit of bulk on either the physical side or special side though so my recommendation would be Celebi
This little guy has a 100 in each stat meaning it can be very bulky on either side, or even both.
You need a slow Pokemon, and Celebi has 100 base speed but you don't need to invest in speed and you can also give it a speed - nature.
Hope I helped!