Kollikodon lived in the Late Cretaceous period, during the Cenomanian age (99–96 million years ago).

Several other monotremes are known from the Griman Creek Formation, including Dharragarra, Opalios, Parvopalus, Steropodon, and Stirtodon.

The strange teeth of Kollikodon, when seen from above, resemble hot cross buns, traditionally toasted and eaten on Good Friday.

[6] Assuming the accuracy of such a guess, Kollikodon would be a contender for the largest Mesozoic mammal known, along with other possible giants such as Repenomamus, Schowalteria, and Bubodens.

The description of the upper jaw showed that it was strongly specialised, with molars being subdivided into numerous rounded cuspules, some of which exhibit pits, possibly the result of crushing hard items.