>>14738317That'd be Legion. They're 'dragons' but tyranid+squigs (for the lesser beasts anyways) is a good description of them.
>>14738263There are a couple of casters that can run all-jack armies, but its still advisable to have a couple of support pieces in as well.
Khador has Karchev, pButcher and pVlad can be an all-jack caster as well, though pVlad would prefer to have some infantry support as well. All of them still want the wardog.
Ret's jacks pay an extra point a piece for utility in general so they tend to be overpriced as anything other than a support piece (rather than facebeater like everyone else's jacks) so they can't really do it with any caster.
Menoth can do well with jack lists as well, with almost any caster, but they NEED their support pieces to do it (choir, vassals, etc)
Cryx has Mort who is probably the best jack caster in the game. Her tier list (one of the few competitive tier lists and probably the best tier list anyways) as it is normally has the requirement of "No units at all" but you still want the solo support (warwitches primarily)
Cygnar can go with Kraye and maybe some others, I don't know.