Complete the party host's slightly exasperated text message.

You really _____ all these expensive appetizers, Harold! The catering company had already set up a massive buffet before you even arrived.

The correct answer is needn't have brought.

When "need" is used as a modal auxiliary in the past, needn't have + past participle indicates that an action was performed, but it was completely unnecessary.

"Needn't to bring" is incorrect because the modal "need" must be followed by a bare infinitive (without "to").