The Sims 2: Pets

The dog with the glowing eyes goes to the sidewalk automatically. If it's near your house feed it right away.
Wait till it bites you and you'll become one.

If your lot has trees you'll be more like to get the leader wolf.You have to befreind it at least up to 60 in daily relationship for it to bite you. It comes only at night and leaves a little before midnight.

Try placing lots of trees and bushes on your lot. Having babies and toddlers in your family also increases the chances the wolf will visit. You need to keep an eye out for the wolf and rush out to greet it as soon as it arrives. It might take a few nights to get your relationship high enough for it to bite you. Oh and having a sim with a knowledge aspiration can help with announcing when the wolf has arrived if the sim has the "see wolf" want. Although this can be filled when any big dog visits the lot, it's worth pausing the game and checking the lot just in case its the leader wolf. Good luck :)

I would go with what twee says! :)

OK. My way of becoming a werewolf is very fast and very easy.
1. Go to neighborhood and hold ctrl shft c
2. A text line shud pop up on the top of the screen
3. In it, type boolprop testingcheatsenabled true
4. Now go back to lot and hold shift while clicking the mailbox
5. A bunch of options shud apear, click spawn NPC
6. A bunch of names shud pop up, click leader of hte pack
7. The dog with the glowing eyes shud pop up at either end of the lot (This may take a few seconds)
8. Hold shift and click the dog, click on the option *MAKE SELECTABLE or something like that
9. The dog's face shud apear in the selectable charactors side thing
10. Hold ctrl shift c again and this time type boolprop controlpets on
11. Select the dog and have him bite ur sim
12. Ur sim is now a werewolf, turn other sims into werewolves by clicking on them and selecting ravage or something
13. HAVE FUN! :D