Look for the green arrow on the maps. (Name of the closest NPC on the map.)
Find Regent's Square Cat - Near entrance of Scotland (diagonal from Sir Reginald Baxby)
Find Hyde Park Cat - By the south entrance of the gazebo near the Greenhouse (Mr. Rowley)
Find Chelsea Court Cat - to Ernest Haldings's right (Earnest Haldings)
Find Ironworks Cat - the ramp behind Pops O'Leary (Pops O'Leary)
Find Digmoore Station Cat - from the entrance, just past the left wall. (Sherlock Bones)
Find Scotland Yard Roof Cat - left corner facing away from the Knight's Court entrance
Find Newgate Prison Cat - near Officer Malone, by the teleporter, next to the actual prison
Find Knight's Court Cat - by Knight's Tower
Find Katzenstein's Lab Cat - near Dr. Von Katzenstein
Find Big Ben Cat - from the entrance of the 12th floor, behind the first crates on the left.
The 12th floor is right after the floor with the silver chests.
Map impossible.