It was freaky.
I like tatoeba’s suggestion as he was curious. Here we have it was freaky. Do I have to laugh or cry? In my far from perfect English those are two different things. Reverso gives me for curioso :curious, funny, interesting and for freaky : strano, freaky and strambo. Sembra molto divertente and freaky!
Sometimes with strange translations, idioms, and colloquialisms, I’ll add a hint.
… and sometimes … it’s best to just change the whole translation.
This appears to be one of those times!
In my opinion, this is completely wrong here. Say, this the first time I see the Italian word “curioso” and then having proudly learned it here I would honestly think that childrens’ animation series Curios George should be Freaky George. No, just wrong.
Is that a hybrid English-Italian version, somewhere between “Curious George” and Curioso come George 
?
… and why isn’t the Italian version Curioso come Giorgio 
?
As for the translation, well if I saw “freaky” as the English and was searching for the Italian, then curioso wouldn’t be the first word that came to mind (in fact, for me, curioso wouldn’t come to mind at all).
However, if you take definition of curioso on Treccani, then description number 3 might means that this is a valid translation -
Agree, not the first choice, and have my bizzarro and curioso concepts in two separate compartments, but I have to admit that Treccani is onto something . You are curious when you see something bizzare.