Using PE RNP complexes, we introduced user-defined somatic mutations in zebrafish with frequencies as high as 30%. Interestingly, PE-induced alleles in zebrafish showed not only the desired edit but also other unintended mutations including insertions, deletions and pegRNA scaffold incorporations. We also found that human pathogenic variants introduced into the zebrafish tyr and kras genes by PE can be successfully transmitted through the germline, demonstrating that PE can be used to generate animal disease models. Moreover, we delivered PE RNP complexes into human HEK293T and human primary T cells and successfully introduced desired edits with frequencies of up to 21% and 7.5%, respectively.