Oxygen Algae (氧气藻; pinyin: yǎngqì zǎo) is a plant and an environment modifier in both Plants vs. Zombies Online and Plants vs. Zombies: Journey to the West. It is an aquatic plant, and as such can only be planted underwater. Since most plants cannot be planted underwater, the Oxygen Algae must be used. When planted, the player will be able to plant any other plant in a 3x3 area around it in Plants vs. Zombies: Journey to the West, or a cross-shaped area but can also upgrade the oxygen range by spending sun on it in Plants vs. Zombies Online.
Plants vs. Zombies: Great Wall Edition/Journey to the West
Oxygen Algae was obtained in the Underwater World. It provided oxygen in a 3x3 area around itself.
Plants vs. Zombies Online
Initially, Oxygen Algae releases oxygen in a cross shape around it to let land plants survive in the aquatic environment. It has a meter below it with 3 sections, which is used to show the level of Oxygen Algae. The player can click on the Oxygen Algae to level it up by spending some sun.
- The first level costs 75 sun and makes the oxygen-supplying range become 3x3.
- The second level costs 125 sun and makes the oxygen-supplying range become a diamond shape.
- The third level costs 200 sun and makes the oxygen-supplying range become 5x5.
Plant Food effect
Its Plant Food ability is to heal all plants around it into its maximum health.
- Algae is actually neither plant, animal, nor fungi. Algae is usually a single-celled organism, however, multi-cellular algae are not unknown to exist.
Specific to Plants vs. Zombies: Journey to the West
- It was originally introduced in Plants vs. Zombies: Journey to the West but then moved to the Great Wall Edition due to the deletion of the game.
Specific to Plants vs. Zombies: Great Wall Edition
- If it got eaten, the player had 5 seconds to plant another Oxygen Algae before all plants in the 3x3 area where it once was drowned.
Specific to Plants vs. Zombies Online
- It is the first plant in Plants vs. Zombies Online to be upgradable during the level without the help of a seed packet.
- Ironically, it cannot be upgraded from the Greenhouse.