Heh, the Croagunk won't be super hard. I got it all figured out. I bred a 31 Speed ditto with a World08 Lucario (heh) and hatched eggs till I got a female. Then, I evolved Riolu into Luke and bred her with my quad flawless Bidoof (the reason I'm doing this whole process is because of this Bidoof). After I get a male Riolu with at least 31s in Attack and Speed, I'm going to evolve it and breed it with my Croagunk. Once I get a good female, I'm going to go find a Machop/Machoke/Machamp, level it up till it learns Cross Chop, breed it with the female Croagunk till I get a good male with Cross Chop. The second to last step is breeding the good male Croagunk with Cross Chop with the female until I get an a good Jolly female. I'll then attach an Everstone and breed her with the male Gunk from ^ until I get a Croagunk with: Cross Chop, 31s in Attack and Speed, a Jolly nature, and Dry Skin. I'll try to get decent IVs in the other stats, but ya know, it's a lot to do so don't be too disappointed if they're not amazing. Besides, Toxicroak is a sweeper, no? And sweepers don't need amazing defenses because their goal is to OHKO everything in site. Ahh, I guess it needs to SD up, so I'll try to get a Gunk with good HP, as that will essentially cover the Sp. Def need (for Psychics) and the Def need (for Grounds). Plus, we have a poke using Signal Beam, no? Ok, anyways, I'll get back to work. Wish me luck.
EDIT: Damn, I need that "Shut Up!" emblem. Wall of text VMs anyone?
EDIT again: I'll cross out what I've done so far.
Some of the crossed out sections may seem odd. I've gotten a GREAT IVed Jolly female, but I have yet to get a machoke to the required level and breed it with my female.