Here's a bit of an odd tee...
This is the first time that Sonic has appeared on something for St. Patrick's Day. In this case, it's an odd mix of St. Pat's and somehow army-camo-print? Well, both things generally have to do with the color green but...seems a little strange, especially when Sonic himself is colored in the print too?? This tee actually looks like a bootleg because Sonic's skin/beige color looks like it was done in gray...but it isn't, it's simply cut-thru with no ink to the mottled gray of the tee. But him not being blue PLUS the 'gray skin' makes him look rather off-model.
The tee itself has army green cammo sleeves, but a gray body and collar.

The slogan here is "Happy GO Lucky", so, with the green, there's no mistaking it for St. Patty's. The "go" is written quite large and done with yellow ink so that Sonic can come out of the 'o' like a gold ring, and to also emphasize the 'go' part of the saying--because Sonic is always 'on the go/going fast'. So, thought was put into the design...but it still comes across as a tad odd with his off-colors.
This is a Target 2021 item, in the kids/teens section.