I cannot identify a caterpillar

Unfortunatley, I did not get a picture of this caterpillar, but I can describe quite well since it is hard to forget.
First it was about 7 centimeters, had a blue horn, and yellow eyes. Its skin was as pink as a worm, but it had a long black smudge on it's back. It was pretty fast, but it didn't arch it's back up and down as it went along. It was pretty thick. I haven't been able to find it on any websites or in any catologues, so I thought I would ask here.
The closest I had heard of was a green catepillar with a blue horn, but that was all.

Please reply