We found these, and loved them so much that not only did we buy one of each set, we became resellers.
They are 100% compatible with LEGO brand blocks. As far as quality goes, they are as good as you can get - we collect the name brand, and would not sell these if we felt they were a poor value. There is a sample page from the manual pictured.
Slashfin is 16.5" long, 6" high, and 11.75" wide. It is 536 pieces. As pictured, it comes with a steam-powered trike and three minifigs. When pushed along, the mouth opens and closes, and there are spring-loaded missile launchers on each wing.
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