Dead Island
59 Achievements
40-50h
Oh, no you don't
Kill a Ram using tackle skill.
2.2%
How to unlock the Oh, no you don't achievement in Dead Island - Definitive Guide
Skorpion, XBA, The, Pants, Party
Sam B has this skill under the combat tree. The lowest level you can get this at is level five. The ram enemy does not appear until act two.
They are the bigger enemies in straight jackets. Your best bet against the ram will be to dodge his initial attack and let him run into a building or something, then whack away at him until he's very low on health. From there, use a few tackles to finish him off. The skill doesn't do too much damage though, and you'll still have to hit him in the weak spot in the back so it can take quite a few hits. Upgrade this skill to level three for best results.
The, Pants, Party
Sam B has this skill under the Combat tree. The lowest level you can get this at is level 5. The Ram enemy does not appear until Act 2. They are the bigger enemies in straight jackets. Your best bet against the Ram will be to dodge his initial attack and let him run into a building or something, then whack away at him until he's very low on health. From there, use a few tackles to finish him off. The skill doesn't do too much damage though, and you'll still have to hit him in the weak spot in the back so it can take quite a few hits. Upgrade this skill to level 3 for best results.
Harry94, and, Warbear, SNAKE7
The first time you will encounter a Ram is in the beginning of Act II during the Main quest "Ram on Heaven's Door". The only character that has the tackle skill is Sam B. You need to first buy the tackle skill on the skill tree, select all 3 of them so the tackle skill is much more effective:
Be sure to kill any zombies near the graveyard before you attempt to earn this trophy. Focusing on just the Ram without any enemies nearby will make life easier for you.
The hard part, however, is actually killing the Ram with the tackle skill. You want to first weaken it so it has a spec of health left because the tackle skill only does about 20 damage to it which is hardly anything. Once it is on very low health you want to treat it like a bull i.e stand in front of it and wait for it to charge, once it does then quickly simply step to the right or left and it'll run by you and hit a wall thus stunning itself for a few seconds. You need to use this opportunity to tackle it as much as you can. To tackle, all you have to do is sprint with 
into it and you'll automatically tackle it. Keep doing this until it eventually dies, it might take a while given the tackle skill is virtually useless against it.