Mike Mearls said:Taking a cue from the 4th Edition Monster Vault and the 2nd Edition Monstrous Compendium, we're providing more information on each monster's personality, ecology, goals, and place in the world. More importantly, we're drawing links between different monsters. For instance, we expanded on hags to make them monstrous fey with a whole network of other creatures that serve or ally with them. They create animated scarecrows, use a horrid curse to turn those who betray them into redcaps, and hire mercenary yugoloths when dealing with truly formidable enemies.
Mike Mearls said:Beguilers and Liars. The demon lord Graz'zt created the jackalweres to serve his devoted servants, the lamias. Reaching out from the Abyss, he bestowed jackals with the gift of speech and the ability to assume humanoid forms. A jackalwere is born to lie, and perceptive creatures might notice it wincing in pain when it speaks the truth. Though it can hold its own in combat, it prefers to fight alongside jackals and others of its kind. A pack led by a jackalwere will flee from tough opponents, only to circle back to attack from ambush or murder foes in their sleep.
I'm fairly certain this is the key reason they are doing this. For a lot of DMs, especially new DMs, it's easy to look at a monster and say "Ok, so it's a Sphinx...it's a lion with a human head...but...well, what do I use it for? When would it likely appear?"This just doesn't do anything for me. It looks like more examples of the needless lore changes that happened in 4e. Maybe it's part of some larger compelling story that we aren't privy to, but it just feels like Graz'zt is getting tacked on. And the lamia - jackalwere connection is what? They can both mimic human sounds so they must be related or serve the same master?
I get that it helps with encounter building as a DM to go, "OK, the PCs are going up against a Cult of Graz'zt, so that means 6-fingers cultists, cambions, lamia, and jackalweres."