In the Login Items pane, you can highlight an item, then right click (or control-click) to select Reveal in Finder. The window that the item is in will then open.
Unfortunately, I already removed it and I don't see it as an option when I click "+".
Did you happen to install a LeapFrogConnect app recently? LeapFrog like the interactive children's toys? My son got some talking dog today that requires computer customization, and after I installed the LFC app, I now have 'Monitor' in my Login Items.
Revealing in Finder shows 'Apps/LeapFrogConnect/Contents/Monitor'
Hope this helps. Oh and Merry Xmas!