Abdallah is the only son and heir of Mohammed ben Kalish Ezab, the Emir of the fictional Arab state of Khemed.
History
Prince Abdullah in the cartoon
One of Abdullah's many tricks
He is an extremely spoiled, mischievous and hyperactive child who is an incurable prankster who loves to play tricks and set traps on unexpected visitors and his father. After first appearing in The Land of Black Gold, the Emir and his son then reappear in The Red Sea Sharks, when The Emir had been temporarily overthrown in a coup d'etat by rival tribe leader Bab El Ehr. Abdullah is entrusted by the Emir to Tintin's care as a result.
The Emir's son is a serial practical joker whose favourite target is the short-tempered Captain Haddock. At the conclusion of The Red Sea Sharks, father and son are presumably reunited. Abdullah has ADHD as revealed in the television episode of Land of Black Gold.