Cerberus

The Cerberus is a dog that has administered the T-Virus. These dogs are fast but not very powerful.

Attacks
There are two types of ways these vicious dogs will attack the player.

Offensive~ The dog will tackle the player down and feast in bloodlust, which will effect the player's health heavily.

Defensive~ The dog will bite the player's arm, chewing on it in defense. This attack isn't extremely powerful.

Resident Evil 0 and Resident Evil
The Cerberus will usually attack you in pairs and have very random attacking patterns. They will run at you and jump so this give you an oppurtunity to time your shots.

A works fine as long as your timing is right and you aim downward at the Cerberus. With a shotgun, you can wait until they actually jump and you and then fire. This should kill them in one shot and possibly knock any others out of the way, giving you time to prepare for another shot.

Resident Evil 3: Nemesis
These hellhounds now wander the streets of Raccoon City, looking for living flesh to tear up. They tend to make an entrance by busting through a window or jumping through fire. Their main attack is a jumping bite, which causes some damage to your character. The Handgun and the Assault Rifle are the best weapons to use against this foe.

Resident Evil Code: Veronica and Resident Evil Survivor 2 - Code: Veronica
These hellhounds are extremely dangerous. In these games, they can take Handgun bullets without falling once, meaning that they will still run at your character even as it is being shot at. Their most dangerous attack is the arm grab, where the Cerberus will try to rip your characters arm right out of its socket. Use the Handgun or the M-100Ps against this enemy.

Resident Evil 4
They aren't exactly Cerberuses, but mutated dogs likewise to these appear in Salazar's Castle. See Colmillo for more information.