TL;DR: I just caught...a shiny Tentacool in my HeartGold game!

UN-TL;DR: So there I was, surfing on a shiny Gyarados from Lake of Rage, when suddenly a shiny freakin' Tentacool appears.

I have Typhlosion out. I switch him out with Vileploom. After a few misses from both parties, I finally get the Tentacool with a Sleep Powder. I switch out for a low-level Raticate, 10 levels below the 'Cool. It uses Cut. Tentacool wakes up. I use cut again, but critical. I throw ONE Ultra Ball and catch the shiny freakin' Tentacool.

The Tentacool is a Level 30 girl. I named her Diane because. This makes her my fifth shiny (not counting the HG/SS Gyarados from the Lake of Rage. Or the hacked Deoxys I got froma friend) and third Water-type shiny I have.

Discuss.