sadly, hidden street is still really sucking when it comes to updating, i use basilmarket and insoya.com to find item drops, lists are a bit different between the two but...
basil says:
Bottom Production Stimulator
» DROPPED BY 26 MONSTERS
Beetle (72), Black Kentaurus (88), Blue Dragon Turtle (90), Captain (70), Dark Drake (68), Dark Klock (76), Dark Rash (74), Dark Sand Dwarf (32), Ghost Pirate (83), Green Cornian (100), Grupin (53), Hogul (53), Jr. Grupin (33), Lorang (37), Panda Teddy (36), Pepe (60), Plateon (44), Qualm Guardian (113), Reinforced Iron Mutae (45), Retz (36), Skeleton Soldier (57), Star Pixie (35), Tauromacis (70), The Book Ghost (55), Ultra Gray (45), Yeti and Pepe (78)
Insoya list: (in korean but has pics of the monsters =P) http://www.insoya.com/bbs/zboard.php?id=monster_db&page=1
Read the directions, and directly you'll be directed in the right direction. 