Since my brother and I are having trouble capturing Entei, I wanted to know what it's speed stat is. If it's more than 100, I think I'll tell him to use Fast Balls, but if not, the normal Poke, Great, and Ultra Balls.
Entei's BASE speed is 100.
The actual stat at level 40 can range from 76 to 106 depending on nature and IVs.
At Level 40, an Entei with 0 IVs and a hindering nature has an 76 Speed stat.
However, with 31 IVs and a benificial nature, it will have a 106 Speed stat.
So Entei would have a Speed between 76-106.
It's advisable that you don't use Fast Balls on it.