stubbiest
Least tall, thickest
Stubbiest is the superlative form of stubby, describing something that is the shortest and thickest of a group, or more broadly, the most compact or truncated.
Physical features like fingers, tails, or pencils worn down to nubs might compete for the title of stubbiest.
He always reached for the stubbiest crayon in the box.
squat
Crouching on bent legs
dumpy · compact · truncated · abbreviated · blunt · snub · thick · stout · pudgy · tubby
stocky
Short and solidly built
squat · compact · sturdy · solid · burly · brawny · chunky · barrel-chested · broad · muscular
blunt
Dull or tactlessly direct
snubbed · unpointed · obtuse · flattened · truncated · nipped · clipped