Verbs ending with -éer
The best known verb in -éer is "créer (to create), but we can also mention "suppléer" (to substitute) or "maugréer" (to moan). These verbs are not frankly to speak of exceptions since they follow the general rule of conjugation of the verbs of the first group. The only thing is that it is advisable to think carefully about the number of E to put in a row because there can be up to 3 e for the singular feminine past participle: la toile que j'ai créée.
Look, for this verb, the radical is "cré". In addition to that, there is the normal ending for -er verbs: e crée, tu crées... To the past participle, we add a simple "é" (as in "je suis aimé" with the radical "aim"). We then find ourselves 2 é in a row : "J'ai créé". And if there is an agreement of the past participle, we then put a third e: les choses que j'ai créées.