Narcoosees is the only restaurant offering a lobster entree on the dining plan. If you're not on the plan you have the options of Shula's or Bluezoo (at the Dolphin) or Fulton's (Downtown Disney.)
Some restaurants offer items containing lobster (bisque at Chefs de France, hamburger with lobster at Grand Floridian Cafe, lobster roll at Captain's Grill, sometimes California Grill or Flying Fish will do a lobster appetizer)