This baby making its first public appearance, clasped to the breast of its mother Lena, was born nine days ago. It was the third birth in the same gorilla family in seven years.
The youngster, unnamed because keepers cannot yet tell whether it is male or female, weighed in at 2kg (4lbs 8ozs).
It may grow to 91kg (200lbs) if it is female or a massive 200kg (550lbs) if it is male.
The tot is the latest addition to the family of Lena and her mate, Silverback Harry. They already have two sons still living in the compound with them, seven-year-old Kesho and three-year-old Alfie.
Lena is so protective of her new offspring that even Harry comes close only when she gives an inviting nod. Keepers dare not venture too close at this stage. That's why they can't tell the gender of the new arrival.
Zoo senior curator Gerry Creighton said: "We will know, probably in a couple of months from constant observation.
"The youngster will cling to Lena's chest for a long time yet. She will nurse it for about 18 months and even then it won't stray very far."
Mr Creighton added: "We are hoping it is a girl. Harry hasn't yet bred a female and it would be nice for him to have a daughter.
"That would also be enormously helpful to an international gorilla breeding programme that we are linked to." He said the youngster will be placed where it will be most useful to the programme with its details entered in a stud book.