[Scott]

Sadly, you cannot make your own objects. The thing you saw is known as a yeti. Go to your DF:LW folder, make a shortcut to your misson editer on your desktop, then right click and go to properties, In the target box it should say somthing like
"C:\Program Files\NovaLogic\Delta Force Land Warrior\Dflwmedc.exe" (with the Quotes)
Change that to
"C:\Program Files\NovaLogic\Delta Force Land Warrior\Dflwmedc.exe" /showall (with a space before /showall). Then you will have more objects to use.

Or you can always download the updated med if that dosen't work for you. The Win2k/XP and 98/ME versions are both in the DF:LW utilities section.
Enjoy!