Don't believe d20srd! Krenshars are actually already playable: the (cohort) bit is a typo. This places the krenshar amongst those rare few nonhumanoids that are playable by default.
Krenshars have two magical beast hit dice. They are more dextrous, wise and charismatic than humans, but suffer in the intelligence department. Their speed is a bit on the low side for a medium quadruped, but fine compared to other PCs. Their bite and claw attacks won't be doing a lot of damage, which is bad.
Scare isn't very good. At low levels, its supernatural use is roughly equal to a totemist with a krenshar mask bound, but past that the HD cap starts to hurt, eventually leading to its utter obsolescence. The nonmagical option is a jumbled mess (my best guess is that it gives a small intimidate bonus), and will not be discussed in detail.
A LA is obviously unnecessary, and even +0 seems hard to justify (name one thing a totemist can't do better). Still, I'll keep it at +0: there's still some uses for this creature.