If used as a verb, 来たるmeans "come and arrive". (It's originally a compound verb, 来る＋到（いた）る.) We use 来たる when we want to say something/someone very important or that we have long expected comes. 笑う門には福来たる (Happiness will come to a home with smiles.) ついにX-day 来たる！！ (X-day has finally come!!) If used before a noun, it means "coming ....". 来たるクリスマスには、... On coming Christmas day, ....

来る（くる） is a verb which means "come". On the other hand, 来る（きたる） is usually an adjective which means "next" or "coming". I recommend to write きたる as 来たる instead of 来る. For it's easy to tell these くる and きたる apart. Thank you. PS. The photo is actress Erika Sawajiri, right ? ＾＾ ・・・addition・・・ I agree with the explanation made by chihiro_ito san below. 来たる is also used as a verb in the case like she says.

KURU is a verb. KITARU is an adnominal.（It will come one of these days. The following. ） GoodLuck　またね