From the Super Mario Wiki
Pendrils are penguins with drills instead of beaks who appear at Plack Beach in Mario & Luigi: Bowser's Inside Story. They resemble Bumpties from the Yoshi series, save for their beaks, which is reference by their name, which comes from "penguin" and "drill".
Pendrils battle Mario and Luigi by diving underground and then popping out of the ground before nose diving into one of the Mario Bros. Sometimes when they resurface, a rock will be stuck on their nose. If one of the Mario Bros. attack them with the rock stuck on them, the rock will shatter and a Bob-omb will run at the one who attacked. Eventually, the Pendril will dive back into the ground and have the rock off them. Pendrils are sometimes paired with Drillbit Crabs in battle.
Names in other languages
|From English "drill" and 「ペンギン」 pengin, "penguin".
||Pun on Pingüino (Penguin) and Perforador (Drill)
||Pun on Taladro (Drill) and Pingüino (Penguin).
||From Pingouin (Penguin) and Vrille (Tendril)
||From Bohrer (Drill) and Pinguin (Penguin)