Jesus uses a question to teach his disciples. It could also be written as a statement. Alternate translation: "And you would never give him a scorpion ... egg." (See: [[rc://en/ta/man/translate/figs-rquestion]])
A scorpion is similar to a spider, but it has a tail with a poisonous sting. If scorpions are not known where you are, you could translate this as "poisonous spider" or "spider that stings" (See: [[rc://en/ta/man/translate/translate-unknown]])