What does allergic mean anyway?

[LochnarITB]

Each type of beast has an inherent attack speed. Various cats are different. My tauren hunter tamed a savannah patriarch. According to this list it is the third fastest attack at 1.3. There is another group with an attack speed of 1.2 and a single beast listed at 1.0. I don't know if any of these have been affected by the patches, but you might want to take a look. The same page also has other pet abilities listed. Another page, on the same site, lists various skills you can get and the beasts that give them to you when trained.