Sea Cucumber?

My brother and his girlfriend went to sentosa beach yesterday and my brother's girlfriend found a creepy creature in the sea. My brother was so curious that he brought that creepy creature home using a mineral water bottle to capture it.

My brother told my father that he caught this creepy creature and ask my dad what was that little creature that he caught? My father told him is a sea cucumber. I was wondering, are you sure that creature is sea cucumber? My brother doubt too.
My father was suggested to release that poor creature back to the sea. But my brother was thinking that he never keep this type of weird creature before and so now this little poor creature is in my house kitchen now. eeee...


Gross!