Answer: kangaroos

AnswerCrossword Clue
KANGAROOS

They have their ups and downs

KANGAROOS

Aussie jumpers

KANGAROOS

Champion leapers.

KANGAROOS
Boomers.
KANGAROOS
Thick-tailed animals
KANGAROOSHerbivorous hoppers
KANGAROOSLeapers
KANGAROOSHopping animals accidentally sank Argo around the middle of October (9)
KANGAROOSGroup that's called a mob
KANGAROOSOutback marsupials