How would a 'sponge/virus hybrid' organism organism?

I was looking at Alien Planet a few days ago, and one of the alien flora called the Stickball Plant is a 🧽 + 🦠 hybrid. Probably not literally, but rather trait wise as it is an alien.

It made me think, how would an organism that had both the qualities of a sponge and a virus be like? Would part sponge mean it would be a very simple organism lacking any organs or tissues? Would the virus part mean it somehow makes more of itself by infecting another organism, probably on the cellular level?

Could a multicellular organism like this evolve or even exist artificially?