It sprouts quickly after placement (setting Place the mysterious grass). A Mysterious Grass grows and attacks Master Radulov!
Race: Triffid
If you have a picture of this specific mob, you can upload it to File:Mysterious Grass.jpg.
To find this mob in-game, use BACKSPACE to open the World Search window, then enter Mysterious Grass in the Search field and click "Search". Remember, the field is case-sensitive and must be entered exactly as shown.