I completely don't agree with Zupakode's answer.
Dire penguin DOES NOT spawn like any other monster with normal cooldown. It has 8 respawns, and I have never seen any dire penguin and any screenshot with it from Nibelor and Grimlund. This info is misleading.
I have marked respawn location with red colour:
I guess that it is possible to meet 1 penguin each day due to the big number of it's resp locations, but it's hard to define a specific time frame (because of the same reason).
EDIT:
I'm adding 2 spots marked with light green dot.