Possibility also include "adaptation mode" if such exist. I don't discern whether autotrophic/heterotrophic part play only minor role either.
For example sundews are plants (so autotrophic), but they "hunt" for insects to get additional nutrients, e.g. nitrogen. As far as I remember the nitrogen is the main reason for eating other organisms but they also use other substances, including carbohydrates, from their prey.
Just look up kleptoplasty http://en.wikipedia.org/wiki/Kleptoplasty The slugs who most frequently employ it would fit your more restrictive definition. Now, if we're getting technical, they aren't born that way. They steal the chloroplasts, but you didn't say, so I guess you need to revise your expectations again. ;)