The only pokemon that's giving me a headache right now is trying to find a Dunsparce. Never encountered one when Serebii.net says you can find out in the grass at that one farm area or whatever. Any Dunsparce. Never do find out in my game while I can find other pokemon like Sunkerns, Lillipups, psyducks and whatever else up to the Chargestone electric cave.
I think Game Freak and Nintendo never even put in Dunsparces in the game at all. Punking us is what they did since day 1
A whole night just looking for a female Eevee in Castelia City -.- --- "Only fools believe in the goddess' ways." Lightning, Lightning Returns: Final Fantasy XIII Pokemon Black 2 FC:[Derrick] - [3783 6998 1893]
The pokemon I'm having the hardest time finding are in the hidden grottos: female DW Cubchoo, female DW Minccino, female DW Muk (route 9 grotto), and a female DW Herdier (only found males so far). I requested a DW Ditto from the trade boards because I have yet to find one in the grotto in Giant Chasm and was getting too fustrated (been looking ever since I reached Giant Chasm in White 2; it's been over six months now).
Official Cresselia of B/W2 and X/Y Boards; Official Darkrai of PMD: Gates of Infinity Board
This is probably going to sound stupid but I decided I'd catch one of everything possible in this game. I cleared out that one forest, then the Floccesy Ranch, and then I think a few other areas like Reversal Mountain. I figured I'd go to Dragonspiral Tower because why not?
I'm still looking for the Unfezant a few days later. Sucks because I oftentimes go through several Super Repels without seeing shaky grass (and when I do it's almost 100% guaranteed to be an Audino). If there was a way to cause shaky grass to appear WITHOUT actually running on said grass it wouldn't be too terribly difficult/time-consuming.
Edit: by "the Unfezant," I initially caught everything in the grass except this guy but opted from searching when I figured out a way to cause rippling water to appear within reach without directly using Repels :P