No surprise, the ANZAC troops from down under brought mascots with them.
They brought them to keep up the morale and encourage the troops when they weren’t fighting.
The most obvious creatures were kangaroos or wallabies.
The Australians first landed in Egypt where they guarded the Suez Canal.
Their nation used kangaroos and the image of a kangaroo in war drives, conscription efforts and even on the official Australian coat of arms. They turned up at nursing hospitals in England, as well.

Kangaroo mascot (Australian War Memorial photo)
For those who got to Europe, they may have found the weather a little chilly.
Marsupials!
The ANZAC troops gave several kangaroos to the Cairo zoo when they headed to Gallipoli.
According to Neil Storey in Animals in the First War:
“In 1916 here were so many wallabies brought over to England by Australians on their way to the Western Front, they had their own paddock in Portsmouth.”
In addition to the kangaroos and wallabys, koala bears also made the trek.
One unit brought a rooster named Jack, whom they found to be a better watch “dog” than any dog–he attacked any animal that came through the lines!
A koala bear would have been tricky to feed as they prefer eucalyptus leaves, though apparently a number of smuggled koalas and possums are the same rations as horses while at Mena Camp in Cairo.
Glow worms?
New Zealand soldiers brought glowworms–which are just what their names suggest– worms that glow in the dark:
“the glowworm emits light through bioluminescence. Huddled in dank, dark trenches, enlisted men and officers alike turned to the incandescent insects for help, collecting them in jars by the thousands.
“These instant but ephemeral lanterns allowed soldiers to examine intelligence reports, study battle maps or simply read comforting letters from home. According to a 2010 study, just 10 glowworms can provide the same amount of illumination as a modern-day roadway light.”
One New Zealand tunneling unit had a cat mascot, Snowy, who not only kept them company but also attempted to keep the rat population down.
Rats in trenches were only part of the horrors of living in the ground.
Probably the most famous Australian animals were the Australian Light Horse Brigade.
They, of course, were not mascots but fighting animals used to transport machinery and soldiers to the front, they fought along the Suez canal, in the Sinai desert and ultimately arrived in Jerusalem.

Glow worms (Wikimedia Commons)
Tweetables
Australian mascots in WWI: kangaroos, wallabies and glowworms? Click to Tweet
Mates from down under: kangaroos, koalas and a rooster in WWI. Click to Tweet
Glowworms in the trenches: light to read maps in WWI. Click to Tweet
I wonder what became of Snowy.