This study demonstrates the successful generation of gene-edited tardigrade individuals using a modified version of the direct parental CRISPR (DIPA-CRISPR) technique. The researchers used an extremotolerant parthenogenetic tardigrade species, *Ramazzottius varieornatus*, and injected a concentrated Cas9 ribonucleoprotein (RNP) solution into the body cavity of parental females shortly before their initial oviposition. This approach resulted in the generation of gene-edited G0 progeny, with only a single allele detected at the target locus for each G0 individual, indicating homozygous mutations. By co-injecting single-stranded oligodeoxynucleotides (ssODNs) with Cas9 RNPs, the researchers achieved the generation of homozygously knocked-in G0 progeny, which were inherited by G1/G2 progeny. This is the first example of heritable gene editing in the entire phylum of Tardigrada, facilitating *in vivo* analyses of the molecular mechanisms underlying extreme tolerance and opening up avenues for exploring various topics, including Evo-Devo. The study also highlights the broad applicability of DIPA-CRISPR to various invertebrate species.This study demonstrates the successful generation of gene-edited tardigrade individuals using a modified version of the direct parental CRISPR (DIPA-CRISPR) technique. The researchers used an extremotolerant parthenogenetic tardigrade species, *Ramazzottius varieornatus*, and injected a concentrated Cas9 ribonucleoprotein (RNP) solution into the body cavity of parental females shortly before their initial oviposition. This approach resulted in the generation of gene-edited G0 progeny, with only a single allele detected at the target locus for each G0 individual, indicating homozygous mutations. By co-injecting single-stranded oligodeoxynucleotides (ssODNs) with Cas9 RNPs, the researchers achieved the generation of homozygously knocked-in G0 progeny, which were inherited by G1/G2 progeny. This is the first example of heritable gene editing in the entire phylum of Tardigrada, facilitating *in vivo* analyses of the molecular mechanisms underlying extreme tolerance and opening up avenues for exploring various topics, including Evo-Devo. The study also highlights the broad applicability of DIPA-CRISPR to various invertebrate species.