Parents: <Slaking + Lopunny3
Shared Egg Group: Field
Offspring Name: Slapunny
New Type: Normal
New Base Stats: 118/128/102/85/91/113 (637)
New Ability and Desc: Hapless: User cannot do anything for 2 turns (basically Truant effect, so loafing around for 2 turns) and all items (including Mega stones) cannot be activated for 2 turns(Klutz+Truant, basically making it completely helpless for the first two turns it is active)
Notable Moves: High Jump Kick, Return, Frustration, Baton Pass, Healing Wish, Entrainment, Ice Punch, Thunder Punch, Power-Up Punch, Quick Attack, Agility, Facade, Retaliate, Last Resort, Sucker Punch, Play Rough, Gunk Shot, Pursuit, Rock Slide, Earthquake, Slack Off, Encore, Drain Punch, Substitute, Focus Punch
Role Identification: Slapunny is a very strong, very fast physical attackers, with access to a variety of coverage and a strong STAB attack. It also has great bulk, 118/102/91 is pretty good. It will most likely function as a bulky attacker and a wallbreaker, after it survives its first two turns of helplessness. It also has a neat support movepool, including Entrainment for gimmicks, as well as Encore, Agility, Baton Pass, and Healing Wish to support the team. The main reason to use it however, is for its Mega:
Parents: <Slaking + Lopunny3
Shared Egg Group: [MEGA]
Offspring Name: Mega Slapunny
New Type: Normal / Fighting
New Base Stats: 118/188/112/85/91/143 (737)
New Ability and Desc: Scrappy
Notable Moves: High Jump Kick, Return, Frustration, Baton Pass, Healing Wish, Entrainment, Ice Punch, Thunder Punch, Power-Up Punch, Quick Attack, Agility, Facade, Retaliate, Last Resort, Sucker Punch, Play Rough, Gunk Shot, Pursuit, Rock Slide, Earthquake, Slack Off, Encore, Drain Punch, Substitute, Focus Punch
Role Identification: Mega Slapunny is a force to be reckoned with. Once it has survived its2 turns of pre-Mega helplessness, it can mega evolve and destroy pretty much everything lol. Scrappy and unregistered STAB attacks is great, and is really powerful coming off of 188 base attack, and it outspeeds the majority of the meta, rolling in at 143 base speed. High Jump Kick and Return/Frustration both have over 100 BP. With access to recovery via Drain Punch or Slack Off and potentially crippling of its counters via Entrainment with its pre-Mega ability makes Mega Slapunny very dangerous. It can take advantage of these turns to set up a Substitute and demolish opponents with a SubPunch set, or it can use PowerUp Punch to get chip damage and give its main attacks more power.
I know Mega Slapunny is going to be really really good, but hopefully two turns of complete helplessness that reset if you switch out in its pre-Mega form is enough to make up for this (giving the opponent two free turns can have huge repercussions, but some people will still use it for the high reward at the end). The way I see it Mega Slapunny is high risk high reward--it is a risk to give the opponent 2 free turns, but the reward of 188 Atk and 143 speed with strong unresisted STABs is excellent.