Weezing

Weezing makes for a fantastic defensive Pokemon in UU, possessing useful resistances to Fighting, Grass, Poison, and Bug, an immunity to ubiquitous Ground-type attacks, and only a single uncommon weakness, all backed up by a sweet Defense stat. While his lacking Special Defense leaves him vulnerable to powerful STAB attacks from that end, he maintains the ability to switch in on a variety of threats and threaten them with his surprisingly large movepool. All in all, while Weezing may not be up to par with behemoths such as Skarmory or Hippowdon in OU, he has anchored himself as a top-tier wall down in the bright and ambitious little UU tier.