棺 is a Japanese kanji written with 12 strokes, listed here under the keyword “coffin”. It is built from 官 (bureaucrat) and 木 (tree). In Remembering the Kanji by James W. Heisig it is frame 1364.
On KumiJi Glyph Explorer, open the parts search and type “bureaucrat” + “tree”. 棺 is among the results, together with every other character containing the same shapes.
Open 棺 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.