go to old olney and there are loads of them
OR
You can go to the Deathclaw Sanctuary, I'll give you a link to where you can find it: http://fallout.wikia.com/wiki/Deathclaw_Sanctuary
This should contain a picture of what locations it is near.
(The deathclaw sanctuary has 6-12 deathclaws in it so don't go unless you have a high level character, also you can find the Bobblehead for endurance there.)
A deathclaw is an irradiated cat basically.
In the Old Olney Sewers, near the southern part. Bring a dart gun and/or powerful weapons for the Deathclaws.
There are no Mounts in the unmodified version of Fallout 3.
There is no more a master key in Fallout 3.
You can find President Eden in Fallout 3 at Raven Rock, but he is also a computer!
go to games for windows find the fallout 3 dlc buy it and you will have it
you can not find any energy cells in Fallout 3 after you find the ones with the alien blaster, you are limited to that number
No, you can only craft, find or buy the dart gun in Fallout 3.
You would need to have the PC version of Fallout 3 and download a mod.
fallout3nexus.com
find who
Yes, you have to kill people on Fallout 3 because they are trying to kill you. You also have to kill them to obtain their armor, weapons cache, food and other supplies. There are also super mutants, ghouls, radroaches, radscorpions, raiders, super mutant behemoths (5), Deathclaws, Mole Rats, Vicious Dogs and other things that also need to be killed in order for you to survive