Actually he said "un loco lindo".
Er, yes, I realise that.
I've linked "random tweet" (highlighted in purple) to the original tweet in Spanish.
... it roughly means someone who's "crazy" but in a nice way, a charming person.
I think the nearest English equivalent would be something like "wild and crazy guy" or "wacky guy", "far out", a charming eccentric (a bit wordy), or possibly "free spirit".