What is "@" "at" called when giving an email over the phone?
Is it different in different regions? I have heard it as "XiaoLong ..." or something similar to that in Taiwan, but not sure what exactly they are saying.
As pointed out by @Daniel Yeung above, they call it 小老鼠 (Xiao3 Lao3 Shu3）in Taiwan, which means 'little mouse'. Takes a little imagination to see the resemblance.
I think that is precisely what you heard over the phone.