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I saw this movie as a kid so I can only recall certain scenes from it but the general idea is that some kind of tentacle alien invaded a town and a team of scientists and soldiers were sent there to contain it.
The most vivid scene I remember is when the tentacle oozed through the streets and grabbed a scientist wearing a white hazmat suit by the legs and filled his suit with some black liquid up to the top. He then fell down, his hazmat helmet glass broke, then momentarily woke up and spoke some dialogues before dying for good.
Another scene involves one of the main characters walking through the street back to the research trailer when he was stopped by a dog (which is probably infected with the tentacle). He then said something along the line of "I just want to help out humanity" or something similar before the dog lets him continue on. I think they were trying to research a cure or something to fight the alien with at this point.