If I had to guess, I'd say that's a picture of some aquatic animal. Maybe a puffer fish? Or a sea lion?
In all seriousness, none of us here are u/s techs, so we won't be able to help you with this one. Also, one-off threads like this are frowned upon in the month boards (you'll see, if you look a bit closer, that we have a thread devoted to u/s pictures). Perhaps find the month board for your due date (if you're 18 weeks right now, that would be June) and post this to the ultrasound thread there. This group is for moms who are due in February.
Re: never mind
In all seriousness, none of us here are u/s techs, so we won't be able to help you with this one. Also, one-off threads like this are frowned upon in the month boards (you'll see, if you look a bit closer, that we have a thread devoted to u/s pictures). Perhaps find the month board for your due date (if you're 18 weeks right now, that would be June) and post this to the ultrasound thread there. This group is for moms who are due in February.