I know that when you're a higher level the lower level creatures don't give you that much XP! I was just wondering since I'm a rank 9 Monstrologist and I was wondering if anyone knew what was the best Creature to farm for the most XP?
Go to higher worlds. There are undead in Krokotopia, parts of Mooshu and all over Dragonspyre, for example. There are Wyrms (dragons) in Dragonspyre and all over Avalon.
There are now trees in Mooshu, Wysteria and Celestia. There are parrots in Azteca. There are boars in Grizzleheim and pigs in Wysteria.
Basically, go exploring. You get the most xp from fighting various creatures and the higher rank they are, the more xp you get.
The Fire-Spitter Spawn in the Poisoned Well have been doing me miracles. They can be found in Avalon, the High Road to be specific. You're gonna need Extract Wyrm, so be prepared for that expense. Otherwise, they're not too difficult to farm, and they've gotten me from Rank 10 to Rank 17. I was averaging about 66 xp per fight at rank 12, without double xp or animus.
I got by with Hitojini Deathcasters from the puzzle in the Pagoda Gauntlet. Four undead, right there, and it should work for many different ranks due to the tier thingy they use with those gauntlets.
Another neat idea might be to have an AoE trained and go to Sunken City since you got lots of low-ranking undead there, and iirc you can fight 3 or 4 at once.
For higher ranks, Mother Ghulture gave me 1 extra animus per minion. Not sure if that was a bug or not (and if it was, if it got fixed recently), but you get the bonus animus from defeating those minions twice. For the last rank, the Packman maze battle has 4 undead against you, though I do find that one tedious.