A wet pet food is formulated to be served to a pet in a first form or in a second form, and the first and second forms of the wet pet food have the same ingredients and about the same amounts thereof relative to each other but different viscosities relative to each other. In a preferred embodiment, the first form is a ready-to-eat chunks in jelly, the second form is chunks in gravy, and heating the wet pet food changes the food from the first form into the second form. For example, the wet pet food can comprise meat chunks and further comprise a thermo-reversible hydrocolloid composition the wet pet food can have a “chunks in jelly” form when served while having a temperature below 30° C. and can have a “chunks in gravy” form when served while having a temperature above 30° C., such as about 35° C.
