To celebrate their arrival, Marwell is offering free entry to the zoo from 25 April to 1 May for anyone named Gary or Lemmy.
While the pair settle in to their new home, the zoo, near Winchester, said sightings cannot be guaranteed but visitors can see them from the fenceline near the Okapi playground.
Meanwhile, the zoo’s escaped capybara remains at large.
Nine-month-old Samba went missing on 17 March, prompting huge search efforts involving thermal drones and a specialist sniffer dog.
Zoo chief executive Laura Read said on Thursday: “We just want to bring her back and make sure she’s safe and well looked after.”