Transformers: War for Cybertron

Once you beat Trypticon and he is lying on the floor and is using his tail attack and etc. he will start talking again. At this point just get as close to him as possible because he is about to fall. If you stand right in front of his chest then you should get hit and get the achievement.

BOSS GUIDE
Typticon may seem impossible with all of his high damage attacks but here is what you have to do to beat him. During the battle (note it is during your third fight with him in this level) he will use an attack that makes him raise his tail and shoot projectiles. If you look at his tail you can see that you can stop his projectiles by destroying the parts on his tail that spawn them. If you focus on destroying them than the fight will be A LOT easier. Once that is done Trypticon should have a big red power core right above his head. Focus on that and then the other power cores on the left and right sides of the first one. Once this is done you've beaten Typticon and the Autobot campaign.

BATTLE TIPS:
1. When Trypticon is making some weird blue spear looking things attack you (the very first attack he does in this form) transform and race around to dodge them.
2. When he is shooting blue orbs out of his mouth just run left or right with an occasional dash and you shouldn't get hit by a single one.
3. For the tail there is no way to be sure that you'll dodge it but run in the direction opposite of where you think its going to hit and right before it does double jump into the air for a greater chance to dodge it.
4. When the dark energon crystals come up aim for his power cores but be sure to check for spiders nearby and kill any that are.
5. There are ammo packs on both sides of the arena and health cores in front of Typticon.

With these tips you should beat Typticon with minimal damage, and complete the Autobot campaign with the "First We Crack the Shell..." achievement in your collection.

This is during Chapter 10 of the Autobot campaign.

Very easy achievement. After Trypticon is beaten, run up to him and get to the edge of the area (the place where you are standing, he'll be right in front of you.) Stand right there and be in front of his face, he should smash you there. Don't worry, no more fights after that, so when you DO get knocked down, the fight's over and you'll hear a bleep bloop and get this achievement.