- This card might have been the reason Gem/Jewel Beasts were changed to Crystal Beasts between the OCG and the TCG. The reason for this is because cobalt is not technically a gemstone, unlike the other "Crystal Beasts" which each feature a gemstone: ruby, amber, topaz, emerald, sapphire, and amethyst. It is plausible that cobalt was confused with the gemstones copal or coral.
- This card resembles a bald eagle.
- This card could also refer to cobalt blue, the blue pigment made of cobalt metal, aluminum, and oxygen. This is a transition metal salt and has a crystalline structure.
- "Crystal Beast Cobalt Eagle" is featured in the artwork of the following cards:
- This card is the "Crystal Beast" counterpart of "Advanced Crystal Beast Cobalt Eagle".
- In the Yu-Gi-Oh! GX English dub, Cobalt Eagle's voice and various phrases are based off Maxwell Smart from Get Smart. Cobalt Eagle is voiced by Sean Schemmel.
- Older Spanish prints of this card use the word "regresar" instead of "devolver", which is the official term for "return" in that TCG branch.
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