Monster plants, when released blew up but slowly died down. Why? This has got to be the best past-time other than events hosted by HabboBites.. not biased at all *wink* that Habbo has to offer. What you do is buy some seeds; plant the seeds; wait for them to grow; breed them and get more seeds for free! Who wouldn't love that, as well as the badges you can obtain to boost your achievement score!
 Seeds (when planted) take 2 days to fully grow, after that period you are free to breed your plants with other users, or by yourself. I highly recommend you find another user to breed plants with as you both get a seed rather than when you breed with yourself you only obtain one seed. Here's some ground rules if you're looking into breeding plants:
- Plants can only breed once (potions can be bought to make them re-breedable)
- You can kill plants, just don't treat them for a while and they'll turn into tombstones, you can turn dead plants into a nice comfy compost for you floor!
- When breeding there is a chance that the offspring will 'mutate' (gain a different colour or shape) and there's a slight chance that you fail to get a seed
- Plants have different levels (0-11) depending on the colour and shape of the plant

Now that that's out of the way.. lets actually talk about the plants themselves. Plants are talkative pets that have 2 main components. Their shape and their colour. These correlate with their levels, for example the lowest level colours Fulvus and Aeneues mixed with the shape Blungon or Squarg will give a level 0 plant (these are the bane of existence). Higher level colours include Azureus, Atamasc and Cyaneus, when mixed with higher shapes such as the Abysswirl they will give a level 10 plant. Don't worry if you start off with the lower end of the level spectrum in time and with some luck you'll surely get higher level plants! 
The "Snozzle" is a secret shape obtainable via normal breeding and the lowest level of this shape is 6 and the highest being 11 (exceeding maximum limit). Now, I say this is a 'secret' shape due to the fact you don't need this shape in order to get the final achievement in "shape collector" and it's level rank has no description, it's just left blank. 
Down below is a chart of what level is shape when mixed with a colour produces; 

Plant Shapes                           Plant Colours
Squarg          (Level range = 0-5)         Fulvus         (Level range = 0-6)  
Blungon        (Level range = 0-5)         Aeneues    (Level range = 0-6)
Wailzor         (Level range = 1-6)         Griseus       (Level range = 1-7)
Stumpy         (Level range = 1-6)         Viridulus     (Level range = 1-7)
Weggytum   (Level range = 2-7)         Phoenicus  (Level range = 2-8)
Sunspike      (Level range = 2-7)         Incarnatus (Level range = 2-8)
Shroomer    (Level range = 3-8)         Amethyst   (Level range = 3-9)
Zuchinu        (Level range = 3-8)         Cinerus      (Level range = 3-9)
Hairbullis     (Level range = 4-9)         Atamasc    (Level range = 4-10)
Wystique      (Level range = 4-9)         Cyan           (Level range = 4-10)
Abysswirl     (Level range = 5-10)        Cyaneus   (Level range = 5-11)
Snozzle        (Level range = 6-11)

The seeds used to plant these can be found in the Habbo catalogue under Pets > Monster Plants > Seeds. Happy breeding :)

Thank you,