Fish still is agility. I did it Saturday. What you are seeing is a combination of these three bugs:

  1. If you are on a dedicated server, your thrall buffs never update in the status window on the upepr left. The window is blank always.

  2. If a thrall is ‘satiated’, they have to kill one thing before any stat upgrade percent happens from force feeding. This is true of all foods, not just the agility one.

  3. Sometimes, right after a thrall levels, he needs to kill one thing before the % bonus from foods healing him to his new hitpoint level shows up. Again, all level up foods do this.

Feed your thrall a cooked fish, and go kill a baby deer. You’ll see the 14% AGI show up.

I guess I should say that this isn’t only a display error. They actually do not get the % bonus when it is not visible.