The most USELESS monster.

Trolls are sometimes very useful due to their regeneration. In any case, they are better than minotaurs because with the latter, it's a matter of luck.

Both are suitable for defense, and if there are many of them, they can also be used for attack. But trolls are too slow for attack, and it's harder to assemble a large squad of field dweorgs.

P.S.: In my opinion, medusas are better than minotaurs...
I agree about trolls; they are a good unit, by the way, earth elementals are also not completely useless...

Medusas and minotaurs are completely different units, and the question here is not about uselessness. As for earth elementals, if you compare all alternative elementals that are summoned or recruited in the portal, then they are the last candidate.
Usefulness is determined only by comparison with other units, and if you exclude all those that bring some benefit, then only those that are almost useless will remain.