Das Tier fehlt mir
Duolingo proposses "I miss the animal". "fehlt is third person and "mir" is dative, why is it not "The animal misses me"?
'jemandem fehlen' means 'to be missed by somebody'. This additional twist makes it a bit tricky to translate as the subject of the German sentence becomes the object in the English translation. 'The animal misses me' would be 'Ich fehle dem Tier'. You can also use the verb 'vermissen' which works more like the English 'to miss': 'Ich vermisse das Tier' and 'Das Tier vermisst mich', respectively.