Weezing

Don't underestimate Weezing; thanks to its solid mono-Poison typing, Levitate, and high Defense, it is a very reliable physical wall in the UU tier. Its resistance to Fighting-type moves is especially useful, as the tier is filled with offensive Fighting-types such as Mienshao, Lucario, Infernape, and Machamp. Thanks to Weezing's decent Special Attack and access to Will-O-Wisp, it is not setup bait like most dedicated walls are. Couple that with Weezing's ability to wall foes and provide some momentum at the same time, and it makes for a solid choice on your stall or balance team.

Unfortunately, Weezing's low Special Defense allows special attackers to shut it down completely. Weezing also lacks reliable recovery, which is detrimental to its capabilities as a wall, as Pain Split can only help so much. Its low Speed also means that it'll nearly always have to take a hit before it is able to do anything.