Punching bag - Worst defeder

EQ Slaking is the only option.

I'd use pidgeys so that I don't have to worry about reviving them, and just turn them over a few more times.

Slaking with no Play Rough. Attack with Machamp, and load 2 Dynamich Punches , then use them one after one and finish with fast moves. If you use first DP just after charging, he will probably use his own Charge move( uh you wont let him do it!) before you defeat him.

Second option is Tyranitar with Bite/ no Crunch (probably Fire Blast is the Best option, cause Stone Edge has early damage window). Machamp beating him super fast.

Option i didnt try, but looks promising is Hariyama( Close Combat). Poor def, fairly high CP and Mewtwo should crush him fast

You get more gym XP for defeating Pokémon above 1500 CP (I believe) so anything that’s pretty weak and goes down quick but has high CP will do the trick.

Maybe something like Gengar, Alakazam, Slaking, Tyranitar, etc. where you could easily exploit a weakness. Drop ten berries before starting to take them out

You can take Gyarados, it has high CP and a double weakness to electric, so you can beat it really fast. Or Tyranitar with a double weakness against fighting.

Gyarados and Tyranitar are the two I'd suggest. High CP monsters that fold quickly when being attacked by common Attackers like Machamp and Jolteon. Bring in Raikou or Zapdos, and Gyarados faints even faster. Vaporeon and Rhydon are another couple of good ones.

I remember when I got my first powerful Jolteon - that's when I started being able to get onto Gyms, back in the days when Vaporeon and Gyarados were among the most common gym defenders. My level 20 Jolteon was enough to knock any o

My pick would be Tyranitar. Because of double weakness to fighting, he falls like a house of cards in the fists of Machamp. Maxed Ttar awards something between 30-36 gym XP.