My group is starting a new campaign and one of my players asked about any races that display symbiotic relationships.
Basically, like Venom or Carnage from Spider-Man but in a fantasy setting.
Does something like this exist? It doesn't have to be alien, mind you. We are playing in the Forgotten Realms setting using 4th edition rules. Though if someone knows of a house rules race like this, that's okay too.
Solve it with flavour. Just take a race and reflavour it. Both Longtooth and Razorclaw shifters have a racial ability that triggers when they are bloodied, that could be flavoured as a symbiote kicking in when the host is in danger.
You could go for a Genasi with multiple manifestations, and have each one and the associated benefits determine whether the host or the symbiote is most prevalent. (and later getting a Paragon feat allowing you have two manifestations active at once, and flavour that as some kind of perfect balance)
