You and the landlord are pretty much free to agree that you will pay the mobile home and property taxes as part of your lease. In addition, if your agreement is intended to eventually provide you with ownership of the property, it would be fairly typical for you to pay the taxes on the mobile home and the lot. So the short answer is likely that yes, the landlord can ask you to pay these taxes, and you can agree to do so. However, if you don't think that your agreement was intended to include your paying these taxes, then you need to talk to your landlord and get your agreement finalized and on paper as soon as possible. Ideally, you should have had the agreement in writing, mutually satisfactory, and signed before you moved into the property.