The Sirian Werebull has medium health and is one of the fastest enemies in the game, making it a dangerous foe. Its two attacks consist of ramming the player, which causes the player to go flying into the air, or if the player is not fast enough, it will attempt to gore the player with its horns, causing the same damage as a ram would. It can throw you over a wall using its horns and you could end up lost unable to get back to what you were doing. That can force you to reset your game.
By far, the most important thing a player can do against Werebulls is to keep moving and strafing. Continuously moving prevents the Werebull from catching up to the player, and strafing prevents it from being able to hit the player.
One or two Werebulls can be taken out with the Double Barrel Coach Gun. However, this should only be done if there are weak or easy to avoid enemies near the Werebull, as it takes time to kill the Werebulls because of the long reload time between Coach Gun shots.
Charged up SBC Cannon cannonballs are very effective against groups of Werebulls. A charged up ball can tear through an entire group of Werebulls with ease (compared to the one or two a non-charged cannonball can kill).
If the player doesn't have a Cannon and needs to kill a group of Werebulls, the XM214-A Minigun and the XL2 Lasergun can inflict a significant amount of damage on groups as well.
The Flamethrower can also do major damage to a pack of Werebulls, but several seconds of continuous fire is needed to kill one.
At close range, explosive weapons are not recommended against Werebulls because there is a very real possibility of one getting close to the player while the explosive is in the air, causing the player to be harmed by the explosive's splash damage. At long range, it's a good option. Getting hit by a grenade makes a Werebull do a jump, though, so it's a bit harder to land a second shot.
A zoomed in RAPTOR Sniper Rifle shot will always kill a Werebull in one hit, which is useful for taking them out before they can even get close to the player.
The more direct hits the player takes, the greater damage he receives. Jumping while dodging increases the chance of much smaller damage when getting hit, although the knockback is still retained.
In more confined areas, werebulls are much more dangerous as they can turn around much faster. Aside from the charging attack, they can also stab the player with horns in these situations. The horn stab is not as damaging, but is much more difficult to avoid.