Pluto TV has joined Virgin Media, allowing users to access the on demand service through a dedicated app on the V6 box. It has not been confirmed if the service is available on the previous generation Tivo boxes.
Pluto TV is owned by ViacomCBS, and is a series of thematically created streamed TV channels, many created around a particular series. The service can be accessed on a wide variety of platforms.
Full details of the Pluto service can be found on the dedicated page here.