He has become bigheaded since winning that award.
Depuis qu’il a gagné ce prix, il a pris la grosse tête*.
This win could give him a bighead.
Cette victoire pourrait lui donner la grosse tête*.
No one wants to work with him because he is full of himself*.
Personne ne veut travailler avec lui parce qu’il a le melon*.
He is growing too big for his britches*.
Il a les chevilles qui enflent*.
As proud as a peacock!
Fier comme un paon !
* Familiar language
* Langage familier