I swear most Darkness forces use him. It's annoying. And I am tired of seeing the same combo over and over again. Spit, run, spit, chase + other UB moves sometimes.
Ok, I may not be able to tell you how to beat the Unclean Beast players (and since he's my preferred Demingod...no offense, but it's not in my vested interest to tell you ALL of my tricks!!) but I'll help you with why they're beating you.
A) UB is faster than other DGs, yes...but only very marginally, and not enough that he'll catch you if you keep a modicum of distance from him early on. The thing is, many UB players supplement his speed by getting the 10% speed boost boots right off the bat. If he does, and you don't...then he has the speed advantage. Personally, I get them booties about 8 of every 10 games I play. Speed is my bread and butter on that class.
Spit alone is not going to kill you, even at the very beginning of the game. It doesn't do really nasty damage until later when, I fully admit, it seems to be too much of a good thing for a melee Demigod to have, in my opinion. But just to set the record straight; I have an alternate build for the Unclean Beast that DOESN'T use Spit beyond level 1, and this build is *harder* to deal with than the Spitting UB.
Ok, so I've given you two pieces of info; yes he's faster than you off the bat, but not by much...and yes, Spit is annoying but it won't kill you when the game first starts. Now think of the following....
I don't know about you, but I play the same no matter what Demigod I am using; I try to get levels early on without having to engage the enemy. Creeps, capturing flags, and DENYING those flags from my enemy; fighting them just enough to make them give up on a flag my side holds. I don't feel the point of the game, right from the onset, is to kill everything that moves. The point is to strengthen my Demigod by any means necessary, to build up my Citadel, and THEN go after enemy Demigods. So what does that mean?
Harass, harass, harass. Everyone says the UB is the "perfect harassing Demigod", but the same can be said of Regulus with his Mine/Snipe spam. or the Rook with his Tower creeping, or Oak with his "Shield/Hit/Hit/Run" tactics, or Sedna with her damn "Peck-peck-peck-HEAL-run" tactic. The thing about UB is; no matter what the player does, UB's got two glaring weaknesses early on which you can exploit. They are (you watching here?): ONE, low hitpoints. UB cannot take damage for beans early on. Seriously. Two to three solid hits and I'm down to half hitpoints. TWO, limited mana pool and a REALLY mana hungry early ability. Sure, I can Spit on you. Once. Twice. Then I'm just about done. I won't be spitting again for a nice while. I've also (probably) gimped my income early on as I have spent all my gold on Speed boots and don't even have enough at first for a teleport scroll or any kind of potion.
So what to do? Well, for starters...carry a health pot or three. If you see a UB coming, go where he is not...kill some creeps, capture a flag, go for his partner, attack one of his towers. Early on, focus on getting some levels and NOT on killing him. If you really want him dead, call one of your allies for help. Bait him, make him chase you, get your partner to jump him and keep running away. The UB may feel you've run off and stay to fight your partner; turn back, and surprise the UB. If you get spit on, pop a potion and run away, then go back. You can heal yourself, he most likely cannot.
Also, keep in mind that most players tend to think the UB is really tougher than he is at first. Later in the game, he is a truly scary animal (give me a Heart of Life and NOTHING ELSE and my UB will make most players cry for their mommies) but early on, he just doesn't have the sort of advantage you think he does. Being Spit on isn;t the end of a fight at levels 1 or 2 or 3. Use that to your advantage, and use the tools the game gives you to suck up his mana and then it's melee only. And early on, he just...doesn't...hit...that...hard.
I guess I am saying; use your head, don't psych yourself out, and do to him what he is (no doubt) trying to do to you; make HIM run, make HIM avoid YOU, and don't bother trying to kill him right off the bat. Make him give up on what he needs; flags, map placement, and easy access to Creeps.