Greg James has revealed fish with teeth were circling him after he jumped naked into the Zambezi river at the end of the latest Comic Relief celebrity trek.
The Radio 1 DJ joined a host of other famous faces to travel along the dangerous river, and promised to skinny dip if listeners pledged an extra £50,000, but he admitted he wasn't even thinking about the consequences until it was all over.
Greg confessed: "By that point I was so emotional and elated that we'd finished... I wasn't really thinking about it. I just took all my clothes off, ran into the river, slipped on a rock - I wasn't being very careful, it could have been really dangerous and I could have cracked my head open! But I did it.
"And then a few moments later I saw these fish jumping in there. Little bite-y fish, and then realised quite how stupid that idea was!"
Greg was joined by Spice Girl Mel C, comedians Dara O'Briain and Jack Dee, athlete Phillips Idowu and former Waterloo Road star Chelsee Healey on the Hell And High Water adventure.
And biting fish weren't the only scary things they encountered.
He revealed: "We were really close. We saw crocodiles on the bank next to us and you've just got to keep away from them. The hippos were 10 metres away, and you have to go really slowly past them because you don't want to disturb them and annoy them! They all look at you, and everyone just goes deadly quiet."
The challenge will air on BBC One on March 14, ahead of Red Nose Day on March 15.