Hi,
sure it is possible and there are different ways.
If you want to simulate the whole thing on the server side you should have the map data in your Extension, so that the server can calculate where to move the monster and know which areas of the map are walkable and which aren't.
Then you can have a timer/scheduler that every X milliseconds (e.g. 100-500) updates the monsters' position. Depending on the type of game you're working on, you don't necessarily need to create the whole animation on the server side. For example if the game is tile based you can send the client the destination tile for the monster and it will make a smooth animation from on tile to the other.
If the game is physics based then you will likely need to continuously update the movement vector and let the client smooth the animation out. An example of this is our Space War game, which you find in our Example packages.
http://docs2x.smartfoxserver.com/ExamplesUnity/spacewarHope it helps