Well, I was browsing through the anti-hydra tactics discussed over here previously and I came across a rather interesting use of Reavers (or any fast cavalry for that matter) : Large Monster hunting.
The reasoning is as follows: Buy a unit of five Reavers with a champion and a musician. Move behind the enemy hydra/stegadon/Greater Daemon, ending your move in a long 1x5 line, with the champion at the front. Charge the enemy in the rear next turn. The enemy can't challenge, and can only attack the champion, thus netting a maximum of 1 CR. The Reavers have 3CR, and thus win by 2 (Rear + outnumber). Hopefully the enemy breaks and the Reavers can run them down.

What I like about this is that even if the Reavers fail to break the Hydra, they tie it up for a few turns at least, and should they survive and break, the hydra must pursue, back to the enemy deployment zone. This could even work against a large block of infantry with hatred.
Obviously only usable if the enemy can't challenge.

What do you think about this idea? Workable?

Unless I am mistaken you must attempt to engage as many models as possible on both sides. That would mean you'd have to allow more than just the 1 model to come into contact.

Not if your formation is 1x5. I'm not allowed to change formation during a charge remember? Five ranks. One model wide. Maximum contact IS one model.

That is rather interesting. First thoughts are that it wouldn't work because wounds would carry over...but seeing as it is the champion it shouldn't...I'm rather intrigued.

Perfectly valid but hard to actually pull off though.

doesn work since they got rid of the snaking rules, you now have to be ain a straight line, no bends, which is really difficult for a unit that is that long.

Hmm you know I wonder if purposes losing combat with a fast unit against a infantry unit wityh hatred from behind them would be really effective. Solo charge some reavers into a big block of black gaurd. Hopefully not all the reavers die and then have the BG run backwards. Take the surviving fast cav and hide them from shooters so they dont get all the VP. If i get that desperate I will try it. Never would of thought of it before.

Just to comment - on Greater Daemons and Character choices, the enemy can challenge, as he's technically in a fighting rank. For enemies like Hydras, yeah, looks really solid.

Not very likely.... Esp if they have the ASF banner.

Well, considering the fact that Daemons can challenge, mabye not such a good idea to charge them, but think about the Hatred Dark Elf lord on dragon, or the vamp lord with hatred, or any number of other targets...In this case the challenge mechanic is good for us, since it gaurantees the Reavers will run, and the enemy must pursue...right into a trap, or out of the way or into line of sight. And six cavalry models head to toe is only 8 inches. Not that much of a threat...I'm actually dying to try this! Its got novelty on its side, plus nobody expects reavers to charge anything big...As part of the deception, you could position the reavers so that their formation enables all 5 to shoot at a different target, masking your true purpose (enemy thinks you may just be maximising shots).

The problem with the reaver conga is that charges are stopped just like eagles stop brett lances. I've also used a 1+ save hero in the fron of the reavers. It doesnt work so bad.

By the way there are places in Europe (poland for example) that disallow conga lines for the purpose of combat. Its sort of a house rule but applies across the country (or so I've heard from a Polish friend).

If you mean that they die for the greater good then yes. Unfortunately that's true. But if a 120 point reaver unit can distract (or possibly break) a 175 point hydra, 200 point Varghulf, or whatever, and maybe even get away on the flee, I consider it well worth it. As for it being forbidden, I don't see why. It's perfectly legal, if a bit silly. In any other situation you'd never do this, so it's situational at best. My philosophy? Bring a silly list and I'll play like a silly bugger against it.

hey guys, i just read this thread, and got very exited at the thought of being able to use my reavers this effectively, untill a sad but true thought struck me: the hydra has two handlers, who has 2 attacks each. i dont remember if its strenght 3 or 4, but i recall that they have armour piercing?. Anyway, that means the hydra unit has 3 different targets, so the hydra itself can kill the champion, and each handler may very well kill one reaver too, maybe even 2 each, because the champion will be gone after the hydras attacks.

Or, the handlers kill the champion, and the hydra kills the rest of the reavers, wich is most likely the case.

I hope i'm somehow wrong on this one, so please correct me if thats the case. I have a upcomming 3000 game against Darkelves. I'm beating them this comming tuesday
So i would love to be proven wrong

This tactic is called "torpeding" and it is actually very well known.
In most civilized gaming communes it's considered cheezy and players who use it are usually despised.
Flagellants and Shadow Wolves are most commonly used for torpeding, flaggelents being absolutely ridiculous because 5 of them with champ can tie ANYTHING for at least 2 rounds.
It isn't good only against monsters, it' good against stopping any unit for several rounds and it can also be effective when using it offensively in combined charges.

It might work, but I can say that if anyone tried something like that at my gameclub, they would get banned for life.

It's right up there with things as with goblin kongas to release fanatics in round 1, or Shade+Assasin first-round charges, charging WLC's from more than your range to force them to flee, etc.

Well the biggest problem is the hydra turns around and fries your reavers with its breath.

If you survive this then you need to pass a terror test.

Well, first of all. Yes. It's cheesy. But I would only consider using it against someone that plops down two hydras and about 23 PD...Fight cheese with cheese as it were. Second, the handlers are not in BtB so can't hit anything at all.

I’ve heard this rule often quoted along with it’s partner in crime “can’t form a unit with more than 10 files”.

I have attempted to find these rules in the BRB, but must have missed them. Can you please provide references?

I don't think its cheesy at all. Unwieldy? Yes. Debatably effective? Yes.

No offense guys, but I think folks would be better served by being less concerned with finding tricks to defeat specific units and more concerned with understanding risk/reward & sacrifice/spoils.

Tricks only work once - unless your opponent is impaired/insane/mentally challenged.

I'll sacrifice 300 points to a hydra if it means I can destroy the rest of his army. The thing you can't allow is for the hydra to do what it wants.

And all that said, a Stardragon still remains the #1 most effective counter to a hydra

With Dragon Armour or equivalent.