Nidorina is in the Undiscovered Egg Group

Recently, I've been doing a crazy chain-breeding extravaganza in Generation IV. Here's how it goes:

1.  Start with a male Lapras. Level it up until it knows Rain Dance, Ice Beam, and Water Pulse.
2.  Breed it onto a female Slowpoke that also knows Water Pulse.
3.  Hatch eggs until you get a male Slowpoke with Rain Dance, Ice Beam, and Water Pulse. The Rain Dance isn't really used here, but it's a good thing to have available for breeding to save on TMs.
4.  Level up the Slowpoke until it learns Confusion, mostly because it's neat that Nidorino can get that.
5.  Breed the Slowpoke onto a Nidoran-female. This works because they're both in the Monster egg group, but note that Nidorina, for some strange reason, is in the Undiscovered egg group.
6.  Hatch eggs until you get a Nidoran-male with Water Pulse, Ice Beam, and Confusion.
7.  Level that up until it evolves into Nidorino.
8.  Level up that Nidorino until it learns Poison Jab.
9.  [step redacted]
10.  [step redacted]
11.  Profit!

What, you think that I'm going to give away ALL of my pokémon training secrets? :-p
Oh, and if anyone cares, I have a surplus of Spinarak with Signal Beam and Psybeam.