The Shrillberry is a seed used to get Boomer, the Bigmouth Squiddly Dee. File:Lynseygray Chessington 3.jpg The seed was originally obtained by attending the Moshi Monsters event at Chessington World Of Adventures and completing the tasks set there. Due to both provided codes having gone expired Boomer cannot be obtained. Each code can only be used once for each monster. Once the seed is planted in the garden, the player will have to also plant to other random seeds.