The flower pot is made the same way as in the Baby Plant tutorial, but I used flower paste instead of a cake dummy. The flower pot in the tutorial is much bigger so in order to make the cake topper lighter, I made the inside of the flower pot from polystyrene.
To make the cactus I used Squires Kitchen flower paste, but you can use any paste you like and are used to. Just make sure that the paste holds the shape well. If it is soft and losing shape add some CMC.
To make the pattern on the hat I used the Katy Sue Designs knitting mat. If you decide to buy a different brand make sure that the pattern is quite small.