How We Met: Sally Phillips & Lucy Cooke - 'Her cape caught fire at a Doctor Who party'

Sally Phillips, 44

Following her first foray into comedy-writing and performing while at Oxford University, Phillips (left in picture) co-created sketch shows including 'Smack the Pony'. She has gone on to appear in films including 'Bridget Jones's Diary', and is also a scriptwriter. She lives in Richmond with her husband and their three children

We were at New College, Oxford, together; we met as freshers. She was wearing dreadful clothes: a tie-dyed Grateful Dead T-shit, faux-fur Dalmatian hat and brothel creepers. We hung out all the time; we became known as the lobotomy twins, wearing ridiculous clothes, smiling a lot and looking incredibly vacuous.

I find animals very funny, but she was always crazy about zoology – she had Richard Dawkins as her tutor. I have strong memories of her ecstatic reaction when there was news that a dog whelk was found to have grown a penis on its head as a reaction to pollution. I love the fact that back then – as now – she was less into the cuddly animals: she genuinely loves stick insects more than pandas.

She should have gone into presenting [natural-history programmes] straight away; she's attractive, funny, brainy and puts people at ease. But instead she went on to direct documentaries and comedy for years. So I really respected her when, a few years ago, she decided to chuck it all in and went to live in Brazil for six months to study poisonous frogs. And after that she started making animal films, and became the sloth queen [directing and presenting a one-off TV documentary, a follow-up TV series and publishing a book on the subject]. I even did the voiceover for her documentary Meet the Sloths. I still remember the intro: "It's early morn in Costa Rica – the dawn peace shattered by screams of the sex-starved sloths."

She's more extrovert than I am and more adventurous; Lucy goes to Colombia like the rest of us go to Sainsbury's. I live in the suburbs now, with three kids, and hang around the school gates thinking how rubbish my fairy cakes are, and how I forgot to put the recorder in the school bag. I look at Lucy and I think, yes, she's not normal.

We've both had difficult things to deal with, but we've had each other. After my eldest son was diagnosed with Down's syndrome, I have a vivid memory of being at a dinner party, me and Lucy sat upstairs on the bed and her being very kind – and knowing not to say anything.

Stuff just happens to Lucy. We went to this Doctor Who birthday party not long ago, Lucy dressed as a generic wench with a cape, which caught fire on some tea lights; she was running around on fire as celebrities threw their drinks on her to extinguish it, Bloody Mary dripping down her face. I think it was Matt Smith who eventually rolled on top of her to put the fire out, and she ended up in A&E – which isn't unusual.

Lucy Cooke, 44

After working on comedy series such as 'The Fast Show', Cooke produced documentaries for the BBC and Channel 4 before returning to her zoology roots, producing the Discovery TV series 'Meet the Sloths' and joining the BBC's natural-history unit. She is founder of the Sloth Appreciation Society. She lives in London

We were both into acting and comedy at university and in our first term we did a really funny, surreal musical play together. I think we shared a love of the absurd and laughing at our own expense, and we became best mates. Many people we met were quite earnest and serious academic types, and maybe we came across as a bit frivolous, giggling a lot.

Sally introduced me to smoking. It's not the greatest gift she's given me. I was vehemently anti-smoking at the time, as my mother was a heavy smoker, but when we had exams at the end of the first term, I remember her coming round to my room when I was revising with a packet of Silk Cut, and we smoked the lot.

Once she got a taste for the stage, she was always going to be a comic actress. In one term, she acted in eight plays in eight weeks, including an ambitious one-woman show she directed and starred in based on an obscure Italian text about a lesbian nun.

Once she's into something, she's incredibly passionate about it; when she decided to go to clown school, she didn't go to one – she went and learnt at three separate ones!

When the first of my passion projects [Discovery documentary] Meet the Sloths got off the ground a few years ago, it was always her voice in my head for the voiceover: I wanted the tone to sound wry and nuanced – it was nice to do that with her, after being friends for all these years.

She's very quirky, though we're both unconventional in our own ways – and successful in our unconventional careers: she's just won has a very prestigious if obscure script-writing scholarship from the Ingmar Bergman Foundation, but people don't know things like that about her as what they see are the landmark BBC1 roles such as in Miranda.

One area where we do have different perspectives is in matters of faith. I've never believed in god – at Oxford, I was taught by Richard Dawkins and sitting in church when I was younger I always thought it was all rubbish. But I respect Sally for her beliefs [as a Christian] and she respects mine.

At dinner recently I mentioned that I hadn't graduated and was wondering if it would be funny to finally do that: it turned out she hadn't graduated either, so in March we finally went and graduated together. We arrived late at the ceremony, and got ticked off publicly by the dean for being late. And as we stood there, struggling with uncontrollable hysterics, we were transported back 25 years.

Cooke's two-part natural history special 'Talk to the Animals' broadcasts on BBC1 on Wednesday and Thursday at 8pm