godan verb (-mu), intransitive verb
crawl into; work oneself into
Describes physically crawling into a space, or figuratively working oneself into a situation or group, often with effort or persistence.
猫が狭い箱の中に這い込んだ。
The cat crawled into the narrow box.
彼はなんとかしてそのグループに這い込もうと
He is trying to work himself into that group somehow.