The influence of Mega Evolution leaves it in a state of constant excitement. It pierces enemies with its two large horns before shredding them.
– Pokémon Sun Pokédex
After mega evolving, Pinsir has grown wings and become Flying type. I’m not sure if this typing is better; while it does give Pinsir the Ground immunity, it also gives it some pretty common weaknesses. It looks rather evil, not a Pokemon you’d want to meet in a dark alley at night.
It gets the ability Aerilate, which is shared with Mega Salamence, it makes Normal moves Flying type and gives a 20% (was 30% in Gen 6) power boost.
Stat-wise, Mega Pinsir gains a bit in each stat, but most importantly, gains the most in Attack and Speed.