The Runaway Bride was the second Christmas Special of NuWho. It introduced Donna's tits, and to a lesser extent the woman attached to them. No pockets in that dress, nosiree, no room with all that mammalage taking up space.
In ages long past, SPIDERS! The earth formed around them, and they're SCHPOIDERS!
Meanwhile, as the Doctor finishes working one out on the TARDIS console to the sound of Rose's sobs, he hears a rough, uncivilized, clearly unintelligent beast mumbling behind him. It's a woman in a bridal gown, and she's unimpressed with what's going on, which puts her about a step up from audience reaction.
The Doctor tries to get her to the church on time, but it fails due to her massive bosom throwing off the doohicky. Instead, they end up visiting her reception (which her mother threw without her). Funny her kindly, beloved grandfather wasn't there. "Spanish flu", they called it...
So, short version: SPIDERS! They're making Donna radioactive so they can wake up their babbySPIDERS and devour the world. In response, the Doctor exterminates every single member of the Raccnoss hive, visibly aroused by the unmitigated genocide. It takes numerous promptings from the loudest mouth in the entire British empire to tear him away from the absolutely orgasmic sight of a sentient being crying in horror as her children and entire race are murdered right beneath her. In fact, in another reality she never even joined him in that chamber under the Thames, and he did in fact wank himself to death.
I can't remember but I think it was bad.
S'alright. Catherine Tate was a big star, so having her on the program complaining about the plots and cliches gave voice to the numerous people gathering around the telly on Christmas Day to watch the latest unadulterated trash that passed for entertainment in the mid-2000s. Later, Rusty would realize that such a voice could work wonders on the program proper, and thus was born the third RTD companion.