I'm having a problem with the dreaded lag. I've told the FTB launcher to give me 4k, 6k, and--just to see what happened--2k of RAM. Everytime the lag grows exponentially as I play the game. I don't see any Project Zulu animals either. Using the pack straight out with Realistic world generation. Java updated to the latest jre 1.8.0 60. Lag also happens in Default world generation. Difficulty getting a crash report, but will play until I get one for you. Got it! Out of Memory Error and it looks like Zulu is the culprit.
@Caigan is there a way you can release an updated config folder for the pack to eliminate some of the duplications and irregularities?
It's the zulu fish causing the ticking error from that report. Try and disable them from the config and see if the pack runs for you.