The Elysia Chlorotica sea slug is not like most sea slugs. Scientists refer to this animal as being "solar-powered," since it undergoes many plant-like processes and resembles a leaf! This creature has chloroplasts that allow it to convert sunlight into energy, so yes, it undergoes photosynthesis.
The Elysia Chlorotica sea slug, unlike some of the more exotic animals we see here on Greenamajigger, can be found close to home! By close, I mean the east coast of the United States.
Feeding on algae, this animal has a weird way of sustaining life. It needs to eat plants to maintain its existence, but the only thing that it takes from what it eats are chloroplasts, which help it undergo photosynthesis more easily!
So, is the elysia chlorotica a plant? Yes. Is it an animal? Yes. MIND BLOWN.