Technetium

Technetium is Patrick's pet radioactive jellyfish.

Season 1

 * 109. "Patrick's Jellyfish"
 * 110. "Reality Squid"
 * 111. "The Battle Continues..."
 * 116. "Discoveries"
 * 117. "Krabs"
 * 118. "Back To Normal"
 * 119. "Fortune Cookies Can't Be Trusted"
 * 121. "Livin' With The Retired"
 * 122. "Unlawful Laws"
 * 123. "That Damn Squid"
 * 124. "The Good Old Days" (mentioned)
 * 126. "The Squidward Effect"
 * 127. "Hallohate 2: Haunted House" (cameo)
 * 128. "School Star" (cameo)
 * 131. "Squidward's Suicide" (cameo)
 * 132. "We're Just Setting The Next Episode Up" (cameo)
 * 133. "Viciously Murdering Ourselves So We Can Get Our House Back" (cameo)
 * 134. "The Lost Snail" (cameo)