This is an internet slang emoticon. It is similar
in theory to the
ubiquitous smiley, however it means:
"Your pet beaver is wearing a hard had and
goggles"
"You can't be serious!"
"Yes, i really am, i went to the circus and saw
d8="
Translates to..."I went to the circus and saw a beaver wearing a
hardhat and
goggles".