"hieeelalaooo" does not fit the rules:

• after each consonant letter the bird appends a random vowel letter (l ⇒ la or le);
• after each vowel letter the bird appends two of the same letter (a ⇒ aaa);

rule 1: h is followed by the vowel: i - hi rule 2: i is followed by two of the same letter: ii - hiii

so it should be: hiiilaaalaaa