This is a very special plant and is rarely seen as such a large plant.
It is a Euphorbia lactea. It looks a lot like coral, which is where the name, Coral Cactus comes from. Although this is a little confusing as Eupohriba are actually succulents, not cactus.
Make sure it has well-drained soil and only water when the soil is completely dry.
Pop in a nice sunny spot.
Toxic to pets is eaten.
Delivered in a 15cm plastic pot.