(informal) "octopus leg wiring": electrical setup involving multiple devices attached to one outlet, hence cluttered and carrying the risk of overloading

burden, impediment

Same as above

cephalopod

(formal) [I, we] wish you a happy new year (literally meet a good year)

a Chinese red-headed centipede (Scolopendra subspinipes mutilans)

making an unnecessary addition

Australian white ibis

(lit. one eye, two legs/feet, three courage, four power) "first, eyes, second, feet, third, courage, fourth, power". The essentials of [kendo] in descending order of importance