j.morrow94: El sustantivo es masculino en francés y alemán, pero la palabra viene del griego ἡ τίγρις (fem.) // η τίγρης, y en latín la palabra 'tigris' era femenina en poesía y en Plinio pero masculina en prosa. La etimología ayuda a explicar la situación lingüística hoy en día.
Well, as an italian native speaker I would like to explain that in italian the words "tigre" and "scimmia" are always feminine words. If you want to specify the gender, you have to say "la tigre maschio" or "la tigre femmina", and yes, Rae.F is right when he/she says that native speakers play with their language. In fact, "Il tigre" is only a wordplay, used in an advertisement too. Just to know it, sometimes the male monkey is referred as "lo scimmione", but it's mainly sarchastic.
In Portuguese and Spanish, it is possible that someone gets a moniker from a different grammatical gender. In this case, the moniker "adopts" in the person's gender. This seems to be the case here: tigre is feminine but the person who got the nickname is a man, so now the noun is treated in this specific example as masculine.
It can be a bit confusing but it is not unusual in more informal situations.
The rules in Italian are more complicated than they are in Portuguese.
Portuguese definite articles:
o = masculine singular
os = masculine plural
a = feminine singular
as = feminine plural
Italian definite articles:
il = masculine singular
lo = masculine singular if the next word begins with s+consonant, other consonant clusters, z, or y
l' = masculine singular if the next word begins with a vowel
i = masculine plural for the singular
gli = masculine plural for the singular
la = feminine singular
l' = feminine singular if the next word begins with a vowel
le = feminine plural
Italian is a lot more predictable than French when it comes to the grammatical gender of its nouns. I'm not saying it's perfectly regular (it has exceptions, as all natural languages do), but it has a mostly reliable pattern, unlike the "e" thing in French, which is a myth -- You're thinking of how the otherwise identical feminine form of a word will be spelled with an extra e.
Generally, words that end in
-o = masculine, singular
-i = masculine, plural
-a = feminine, singular
-e = feminine, plural