Please translate this word 抢怪. I checked a bunch of online dictionaries and I can't figure it out. Thanks.

Then you must look in a paper dictionnary, or guess the meaning as if two separate hanzi:
搶 抢 qiāng against wind
搶 抢 qiǎng fight over / to grab / to rob / to rush / to scramble / to snatch

怪 guài queer / to blame

and see if it fits your context.

It may not even be in a paper dictionary as the word seems to be an MMO term. What I'm looking at is a setting in a game program. Has something to do with attacking monsters, I suppose. I'd like to hear an explanation from someone who is familiar with this word.

If anyone can translate it from the context, there's obviously Google, or something like this page. The word is used in this phrase:

此类副本适合不同等级、不同队伍规模的玩家组队挑战，让玩家不用再为抢怪而困扰。

It's not in my ABC Chinese-English Comprehensive Dictionary, so I guess that it is a game-specific term.

Ok, I found enough context with google translate to understand it - the term in English is "KS", or "kill steal".

It is a word from MMO-RPG, you are killing monsters to get exp., golds or other benefited stuff in a area. so these monsters are similar Crops, you think they are belong to you.

But later, a people come, kill "your" monsters, it looks like the rob the exp. and golds which are supposed to be belong to you.

The action of this people is called "抢怪".